Talks
in 2013
TBA
(Monash University)
Abstract
Alex Lumpkin
Fermilab
Abstract
Roger Jones
Daresbury/Yale
Abstract
Jim Zagel & Randy M. Thurman-Keup
Fermilab
Abstract
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Nikolay Solyak
Fermilab
Abstract
Design of the PXIE beam dump and its radiation shielding were investigated. In talk we will discus selection of materials for beam dump, geometry and cooling, influence of such phenomena as material spattering and blistering for the lifetime of dump. Design of the local radiation shielding for beam dump and studies of radiation conditions inside and outside of the cave were done by using MARS simulations. The final configuration of PXIE enclose (the thickness of the concrete floor, roof and walls, the constructions of the entry/exit labyrinths, problem of the groundwater activation) provides required radiation protection for the personnel and environment in all operation scenario.
Timofey Zolkin
Fermilab
Abstract
Recently, a concept of nonlinear accelerator lattices with two analytic invariants has been proposed. Based on further studies,the Integrable Optics Test Accelerator (IOTA) was designed and is being constructed at the Fermi National Accelerator Laboratory. Such a nonlinear lattice may be helpful in suppression of the collective instabilities by introducing a relatively large tune spread in a beam, while reducing phase-space area occupied by chaotic trajectories. Despite the clarity and transparency of the proposed idea, the detailed analysis of the beam motion remains quite complicated and should be understood better even for the case when no perturbations are taken into account. In this presentation we will review one of the three proposed realizations of the integrable optics, where the variables separation is possible in polar coordinates. This system allows for an exact analytical solution expressed in terms of elliptic integrals and Jacobi elliptic functions. It is worth noting that this model is valuable just because of this fact; the existence of the exact solution allows both, the possibility to check numerical algorithms used for tracking and to perform more rigorous analysis of the motion in comparison with the "crude" analysis of the topology of the phase space. In addition we will discuss some difficulties associated with numerical simulations of such a comparatively complex dynamical system (e.g. the use of high-order symplectic integrators) and will take a look at the possible perturbations for a model machine.
Rami Kishek
Univeristy of Maryland
Abstract
The University of Maryland Electron Ring (UMER) is one of the few facilities dedicated to exploration of space charge physics in beams. The ring uses low energy electrons at 10 keV to explore the scaled physics of higher energy proton and ion beams. By varying the beam current (0.5 - 100 mA), a wide range of space charge intensities is accessed. This talk will present an overview of the ongoing research at the UMER facility, as well as potential for future experiments.
Alexander Shemyakin
Fermilab
Abstract
One of the goals of the Project X Injector Experiment (PXIE) is to demonstrate the capability to form an arbitrary bunch pattern from an initially CW 162.5 MHz H- bunch train coming out of an RFQ. The bunch-by-bunch selection will be taking place in the 2.1 MeV Medium Energy Beam Transport (MEBT) by directing the undesired bunches onto an absorber that needs to withstand a beam power of up to 21 kW, focused onto a spot with a ~2 mm rms radius. A ¼ - size prototype of the absorber has been manufactured, and its thermal properties are being tested with an electron beam generating a peak power density similar to the one expected during normal operation of the PXIE beam line. The report will describe the absorber concept, the prototype, the testing procedure with the electron beam, and the latest results.
Sergei Nagaitsev & Valeri Lebedev
Fermilab
Abstract
Accelerating gradients of about 20 GeV/m, recently demonstrated in plasma wake-field experiments, appear to open an extremely attractive and economical way for a new generation linear electron-positron colliders based on the plasma acceleration. Starting with first principles, we will discuss main luminosity limitations of such collider schemes and will show inconsistencies in a set of possible parameters, which have been recently proposed.
Duncan Scott
Fermilab
Abstract
Building on the success of reliable 400kW operations the Nova era will increase the beam power by a factor of 2. This is being accomplished by significant upgrades and major installations of new systems that have been ongoing for the previous year. This talk will give some history of previous operations and then highlight different parts of the new configuration and operating modes, installation and diagnostics. Options and results relevant to the future muon campus and Mu2E and g-2 experiments will also be presented.
Gary M. Carinci
TMR Stainless
Abstract
Stainless steels have given reliable, cost-effective service for approximately 100 years as corrosion resistant construction materials. Although these mature alloys have been used for decades, many of the duplex stainless steels have only been developed during the past few years. Some of the advancements in duplex stainless steels as well as the selection criteria with respect to the corrosive environment will be discussed. Duplex stainless steel properties and corrosion resistance will be compared to the standard 300 series stainless steels and nickel base alloys.
Grigory M. Kazakevich et.al.
Muons, Inc.
Abstract
A high-power magnetron transmitter based on two 2-cascade injection-locked Continuous Wave (CW) magnetrons with outputs combined by a 3-dB hybrid has been proposed. In such a scheme, power control is achieved by varying the phase difference between the two magnetrons, while phase control is provided by the simultaneous variation of phase in both the magnetrons. This allows a fast and precise control of phase and output power, required for individual powering of the intensity-frontier Superconducting RF (SRF) cavities of GeV-scale proton/ion linacs like the Project X CW and pulsed linacs or linacs for ADS projects. The transmitter utilizes vector addition of the signals of the two injection-locked CW magnetrons; operation of the injection-locked CW magnetrons in a 2-cascade scheme allows a large decrease of the locking power necessary for operation within the wide-band control loop. The transmitter is intended to operate within a fast and precise control loop in phase and amplitude. The concept of the transmitter has been verified in experiments with commercial, low-power, 2.45 GHz, CW magnetrons operating in pulsed mode with large pulse duration. The capabilities of the CW injection-locked magnetrons operating within the fast control loop have been verified by measurements of the transfer functions of the magnetrons at the phase control and simulation of the closed loop performance. The measurements and simulation demonstrated capability of the proposed magnetron transmitter to suppress parasitic modulation of the accelerating field in the SRF cavities caused by mechanical noises, low-frequency ripples of the magnetron power supplies and phase noise of the injection-locked magnetrons.
Sergei Nagaitsev
Fermilab
Abstract
Construction of the Advanced Superconducting Test Accelerator (ASTA) Facility at NML began in 2006 as part of the ILC/SRF R&D Program and later the American Recovery and Reinvestment Act (ARRA) within the Department of Energy, Office of High Energy Physics. Construction of the facility was motivated by the goal of building, testing and operating a complete ILC RF unit to demonstrate industrial and laboratory capability for producing state-of-the-art superconducting linear accelerator components, and assembling them into a fully functioning system. It was recognized early in the planning process that an electron beam meeting the ILC performance parameters was itself a powerful resource of interest to the wider Advanced Accelerator R&D (AARD) community. This talk would present an overview of the ASTA facility and the proposed scientific program.
Valeri Lebedev
Fermilab
Abstract
PXIE is being built to address the outstanding issues of the Project X frontend. It represents the first 40 m or in other words first 25 MeV of Project X CW linac. There are number of issues to be addressed by R&D carried out on the PXIE. The most important are: bunch-by-bunch chopper, CW RFQ, low-beta SC cryomodules and the extinction for removed bunches. The talk discusses the present status of the project and future plans.
Mary Convery
Fermilab
Abstract
The Muon Campus plan including accelerator modifications needed to support g-2, Mu2e, and future Muon Campus experiments will be discussed. This plan has evolved from separate Mu2e and g-2 proposals in an attempt to share as much infrastructure and resources as possible. The talk will focus on the history, the current status, and future possibilities.
Talks
in 2012
Vladimir Shiltsev
Fermilab
Abstract
Space-charge effects are currently considered as one of the most important performance-limiting factors for low- and medium energy particle accelerators. We will briefly discuss the nature of the effects and previous ideas and attempts to counteract them. Two novel schemes of space-charge compensation have been proposed recently which employ electron lenses or electron columns. They potentially offer a significant increase of the beam intensity for future accelerator-based high-energy physics experiments and other sciences. We will review theoretical and technical aspects of these schemes and outline the plans for experimental studies of the space-charge compensation at Fermilab.
Michael Pellin
Argonne
Abstract
Photocathodes are crucial in applications ranging from solar photovoltaics to detectors to accelerator injectors. Typically photocathode materials are semiconductors (occasionally metals) whose band gap (<1.5 eV) is sufficient to suppress dark current emission even when the photocathode is set to high potential. Following photocathode absorption of a photon, electrons are injected into the conduction band where a variety of processes can lead them to the cathode surface. If the potential applied is sufficient, photoelectrons can overcome the cathode electron affinity (work function) and escape. The efficiency of the photocathode is a convolution of the absorption efficiency of the cathode material; the efficiency of photo-electron transport from the absorption site to the surface; and of the efficiency of ejection of the photoelectron into the vacuum. The photoelectron pulse width and polarization are also dependent on photo-electron transport. The photo-absorbance of the photocathode is crucial for performance since the photo-electron transport efficiency falls with the inverse distance of the absorption event from the surface squared. At Argonne, we have been exploring the use of plasmonic structures to enhance the absorbance of photocathodes. This approach has several advantages. 1) significant enhancement can be generated (>10x), 2) the enhancement can be tuned to particular wavelengths, and 3) photocathode material choice can be broadened by decoupling the need for absorbance from the other necessary photocathode properties.
Vitaly Pronskikh
Fermilab
Abstract
The Mu2e experiment at Fermilab is designed to study the conversion of a negative muon to electron in the field of a nucleus without emission of neutrinos. Observation of this process would provide unambiguous evidence for physics beyond the Standard Model and can help illuminate discoveries made at the LHC or point to new physics beyond its reach.
Performance of Mu2e essentially depends on how values of radiation quantities in the magnets satisfy the requirements developed so that the experimental setup withstand in the radiation environment during its lifetime. Radiation quantities such as neutron flux, DPA, power density, absorbed dose in organics, dynamic heat load in cryogenics will be discussed.
Shielding of the magnets in Mu2e solenoids will be described along with how they comply with constraints such as quench stability, low dynamic heat loads, lifetime of the components. An account of Production Solenoid absorber (Heat and Radiation Shield) design based on thorough MARS15 simulations will be sketched from first multilayer options to the present all-bronze one.
Another important issue is the neutron flux arising from both primary proton interactions and interactions of muons with parts of Mu2e apparatus. These neutrons can create a high background in Cosmic Ray Veto counters. Calculations of neutron flux in the counters for different configurations of shielding around the Detector Solenoid were performed using MARS15 code and will be presented.
Alex Murokh
RadiaBeam Technologies
Abstract
A unique electron beam parameters space of the Advanced Superconducting Test Accelerator (ASTA) facility at Fermilab offers a possibility to develop an Inverse Compton Scattering (ICS) tunable energy gamma ray source of the unprecedented average brightness. Such ICS gamma ray source could enable wide range of applications, including probing the properties of nuclear matter, synthesis of rare medical isotopes, and development of novel techniques of non-destructive testing and stand-off detection. Initial evaluation of the technical performance, features, and requirements for the ASTA gamma ray source is presented, and its potential role as a test bed for a broader class of ICS light sources is discussed.
Aleksandr Romanov
BINP
Abstract
Aleksander Romanov is a candidate for the Peoples Fellowship position at Fermilab. The presentation will give an overview of his achievements at his home institute as well as possible directions for his work at Fermilab. The discussion will include automatization of a beam based closed orbit correction and linear lattice tuning with modified LOCO algorithm. This will be followed by a report on the proposal of the synchrotron radiation based BPM system at IOTA for the linear and nonlinear optics probing.
Manjiri Pande
BARC
Abstract
The solid-state radio frequency (RF) power amplifier has several advantages over the tube amplifiers. These are mainly high reliability, simple start-up procedure, long life, easy maintenance, low voltage operation and use of low power circulators.
In BARC, solid state amplifier technology development is being done both at 350 MHz and 325 MHz using RF transistors such as 1 kW LDMOS and/or 350 Watt VDMOS. For project X, work is being done at three power levels viz., 1, 3 and 7 kW and at 325 MHz.
The overall configuration of an RF amplifier includes the basic 1000 watt RF module based on LDMOSFET, a no. of power splitters / combiners with different configurations depending upon various power stages, directional couplers, compact DC supplies and an interlock and protection circuit.
This talk for the technical seminar gives an over view of development of RF power amplifier modules, associated technologies and then integrated RF power amplifier with its test results.
Milorad Popovic
Fermilab
Abstract
I will describe a concept of CW Proton Linac on the Fermilab site. Based on output energy linac is segmented in three parts, 1GeV, 3GeV and 8GeV. It is located near existing Fermilab Proton Source with intension that each section of the linac can be used as soon as it is commissioned. The whole design is based on designs suggested for Proton Driver and ProjectX. The suggested sitting and linac segmentation allows for the construction to start immediately. Additional benefits comes from the fact that present linac (the oldest machine in Fermilab complex) get replaced and exiting Proton Source preserve functionally for many years in the future.
I will also describe a concept for a storage ring in the Fermilab Booster tunnel to accumulate 1-GeV beam from the Project-X H- Linac. The ring is made out of permanent magnets, and its primary purpose is to accumulate beam for the Booster. The ability to chop bunch-by-bunch in the linac creates many opportunities to package beam for different users in the proposed storage ring. For example, the stored beam can be used for a Pulsed Spallation Source, for a muon-to-electron conversion experiment based on a 100-Hz FFAG ring (Prism/Prime), and/or for a pulsed beam for Short Baseline Neutrino Experiments. These specially packaged beams can be used either directly or after acceleration in the Booster.
Ian Pong
ITER
Abstract
Ian Pong, currently from ITER and formerly from CERN, will be presenting the challenges related to the production and the application of Nb-based superconductors. NbTi wires are used in the Tevatron and the LHC, among other particle accelerators, and have found successful commercial application in MRI magnets. Nb3Sn was discovered over half a century ago and a few years before NbTi, but it is only being produced in large quantities for the first time for ITER, despite having superior properties. NbTi is a ductile alloy relatively easy to handle, whereas Nb3Sn is a brittle intermetallic compound whose ability to carry current in the superconducting state is sensitive to strain. In his talk, Ian will describe how common NbTi and Nb3Sn wires are produced, and how a cabled conductor is made from individual strands. From there, he will explain how their performance can be affected by various factors and describe some recent research efforts and conductor development.
Sampriti Bhattacharyya
Ohio State University
Abstract
A potential application of proton linacs is Accelerator Driven Systems (ADS, or Accelerator Driven Subcritical Systems, ADSS). ADS is a revolutionary concept where a proton linac produces energy from transmutation of conventional radioactive waste. The major challenge in realizing this concept is combining high efficiency and high reliability in a proton accelerator. For use as a power plant, reliability of >99% is essential, whereas a superconducting linac such as the Spallation Neutron Source (SNS, Oakridge National Laboratory, TN) has <85%. A thorough understanding of reliability is imperative to understanding the feasibility of ADS. In this talk, we discuss the work performed on reliability analysis of Project-X as an experimental test bed for ADS. We use commercial software to model various parts of Project X linac and validate our methodology against SNS data. We further analyze the probable reasons of downtime and explore the use of automated controls to enable quick repairs.
David Whittum
Varian Medical Systems
Abstract
An introduction to the challenges for commercial electron accelerator systems and components, with an overview of design scalings, and discussion of possible research topics relevant to commercial applications in medicine, industry and security.
Puneet Jain
BNL
Abstract
Brookhaven National Laboratory is developing SRF technology for high current beams. One element of this program is a five-cell 704 MHz beta=1 cavity which is highly damped. Such a cavity can operate in Energy Recovery Linac at high currents, typically hundreds of milli-amperes. This cavity will be installed in the coherent electron cooler of Relativistic Heavy Ion Collider (RHIC) and a future electron-ion collider (eRHIC). My research at BNL has focused on the studies related to a 704 MHz five-cell superconducting RF accelerating cavity. In order to achieve the optimum performance of the cavity, it is essential to damp the unwanted higher order modes (HOMs) and microphonics. In my talk, I will present the identification and characterization of the undamped higher order modes (HOMs) using bead pull technique and the analysis of the noise data observed during several past test runs. It is crucial for the running of the cavity to keep the thermal load on cryogenics at minimum. This is achieved by a careful design of thermal intercept on the fundamental power coupler (FPC). I will illustrate thermal calculations done under static and dynamic heat loads. Then I will discuss the specifications of coolant for the effective heat removal from the FPC. I will also present a brief summary of my doctoral work – the analysis of electron cloud measurement technique at KEK B-factory.
Sergei Nagaitsev
Fermilab
Abstract
The use of nonlinear lattices with large betatron tune spreads can increase instability and space charge thresholds due to improved Landau damping. Unfortunately, the majority of nonlinear accelerator lattices turn out to be nonintegrable, producing chaotic motion and a complex network of stable and unstable resonances. Recent advances in finding the integrable nonlinear accelerator lattices have led to a proposal to construct at Fermilab a test accelerator with strong nonlinear focusing which avoids resonances and chaotic particle motion. This presentation will outline the main challenges, theoretical design solutions and construction status of the Integrable Optics Test Accelerator underway at Fermilab.
Ralph Pasquinelli
Fermilab
Abstract
A means for non-invasive measurement of transverse and longitudinal characteristics of bunched beams in synchrotrons has been developed based on high sensitivity slotted waveguide pickups. The pickups allow for bandwidths exceeding hundreds of MHz while maintaining good beam sensitivity characteristics. Wide bandwidth is essential to allow bunch-by-bunch measurements by means of a fast gate. The Schottky detector system is installed and successfully commissioned in the Fermilab Tevatron, Recycler and CERN LHC synchrotrons. Measurement capabilities include tune, chromaticity, and momentum spread of single or multiple beam bunches in any combination. With appropriate calibrations, emittance can also be measured by integrating the area under the incoherent tune sidebands.
He Zhang
Michigan State University
Abstract
A method will be presented that allows the computation of space charge effects of arbitrary and large distributions of particles in an efficient and accurate way based on a variant of the Fast Multipole Method. It relies on an automatic multigrid-based decomposition of charges in near and far regions and the use of high-order differential algebra methods to obtain decompositions of far fields that lead to an error that scales with a high power of the order. Given an ensemble of N particles, the method allows the computation of the self-fields of all particles on each other with a computational expense that scales as O(N). The parallel version based on MPI of this algorithm enables us to take advantage of the cluster machine and deal with huge number of particles. Some numerical examples of applying the algorithm in beam dynamic simulation will also be presented.
Stuart Henderson
Fermilab
Abstract
It is widely appreciated that particle accelerators and their associated technologies have applications that go well beyond Discovery Science. These applications have the potential to make an impact in other areas of national importance, including in medicine, industry, national security, energy and the environment. The Department of Energy Office of High Energy Physics recently formed a task force to provide advice on accelerator R&D stewardship in order to formulate plans for strengthening the coupling between the OHEP R&D activities, and potential applications beyond particle physics and Discovery Science. In this talk I will describe some of the history and motivation for this topic, the work of the task force, the challenges that were identified and the suggestions made by the task force.
Stephen Holmes
Fermilab
Abstract
Budgetary constraints have led to the development of staging scenarios for Project X. The criteria applied to any scenario are that each stage must: 1) be implemented at significantly less than $1B; 2) provide compelling physics research opportunities; and 3) lead towards the ultimate realization of the full capabilities of the Project X Reference Design. This talk will outline the staging scenarios currently under development for Project X, the physics opportunities opened with each stage, and the R&D strategy being undertaken to support these scenarios.
Terry Hendricks
Sandia National Laboratory
Abstract
High temporal resolution heat flux measurements were performed in two different internal combustion (IC) engines. Measurements in a large compression ignition engine were conducted with a wireless telemetry system utilizing fast-response thermocouples mounted on the piston surface. Parametric studies were conducted over a range of operating conditions and different combustion strategies were investigated and compared to one another including conventional diesel combustion and Reactivity Controlled Compression Ignition (RCCI) combustion. The conventional diesel combustion heat fluxes were characterized by the existence of large heat flux differences between thermocouples that are the result of spray targeting and impingement and spatial stratification within the chamber. In contrast, during RCCI combustion the heat fluxes among the different thermocouples were found to have increased homogeneity, and were of lower magnitude, which gave rise to lower piston temperatures. Measurements performed in a small, air-cooled spark ignition engine were conducted with a spark plug-mounted coaxial thermocouple. The single-point measurements were used to analyze the processing method used for the calculation of surface heat flux, and the fundamentals of the surface temperature measurement. It was demonstrated that the advanced inverse techniques utilizing regularization improved the accuracy of surface heat flux estimates by incorporating the temperature variance data. Regularized surface heat flux estimates are intentionally biased yet the regularization procedure does not decrease the overall accuracy of the solution. Inverse methods were found to increase the solution stability by directly calculating the surface heat flux, thus, avoiding amplification of temperature measurement errors common with finite differences used in analytical inversion techniques. The high-load SI data recorded an anomaly during the expansion stroke, where the heat flux reversed direction turning negative and reaching a negative value that was 8% of the peak magnitude recorded during combustion. A 2-D, axisymmetric numerical model of the coaxial probe with an imposed surface heat flux was used to investigate this phenomenon. The simulation results showed that significant lateral conduction between the adjacent thermoelements occurred at the surface and extended to a depth of 150 microns. The temperature bias produced by radial conduction could account for 3% of the observed heat flux reversal seen in the engine data. The presence of multi-dimensional heat transfer effects led to the design and fabrication, of a new array-based temperature sensor capable of recording rapid transient data without 2-D effects biasing the temperature measurement. The sensor was fabricated on silicon using lithographic techniques, but did not survive an engine test long enough to produce usable data.
Vladimir Shiltsev
Fermilab
Abstract
AdA, VEP-1, CBX, ACO, Adone, Spear, VEPP-2, Doris, DCI, CESR, Petra, ISR, VEPP-4, CESR, PEP, SPS,Tristan, Tevatron I, SLC, HERA, LEP, BEPC, PEP-II, LEP-II, RHIC, Dafne, Tevatron II, KEK-B, BEPC, VEPP-2000, LHC, Super-B, HL-LHC, LHeC, ENC, NICA, Tau-Charm, eRHIC, Super-KEKB, HE-LHE, CLIC, Higgs Factory-ILC, HF-Ring, HF-MM, Muon Collider, DWA-LC, PWA-LC, PWLA, DLA-LC, XC-MMC ... "Where to go" and "What to do"
Richard Talman
Cornell University
Abstract
Electric dipole moment (EDM) measurements may help to answer the question ``Why is there more matter than antimatter in the present universe?''. For a charged baryon like the proton such a measurement is thinkable only in a ring in which a bunch of protons is stored for more than a few minutes, with polarization "frozen" (relative to the beam velocity) and with the polarization not attenuated by decoherence. Lattices with these capabilities are described, including one, as an all-electric example, situated in the Tevatron accumulator tunnel. Rings for later measurements of other charged baryons, such as the deuteron or helium-3 nuclei, are more complicated. "Precursor" experiments are also described in which an electrostatic separator borrowed from the Tevatron is used as a prototype bending element in the COSY ring in Juelich Germany.
Kavin Ammigan
IIT
Abstract
Fuel droplet vaporization under asymmetric thermofluid conditions is prevalent in many combustion related devices. Asymmetric thermal radiant heating in particular, is important in spray flames, counter-flow dif- fusion flames, regions close to the walls of conventional combustors and more importantly in liquid-fueled microcombustors. Even though extensive studies on droplet vaporization involving thermal radiation have been performed, the area of asymmetric thermal radiation absorption has not yet been explored. In this talk, I present the results of an experimental study, which uses the planar laser-induced fluorescence (PLIF) diagnostic tool to investigate the vaporization phenomena of fuel droplets exposed to asymmetric thermal irradiation. Results, in the form of PLIF images, reveal highly asymmetric vapor distribution around the droplets with the apparent induction of Stefan flow from the droplet surface, for the case of asymmetric radiant heating. Such phenomena have not previously been reported in the literature and have relevance to the overall fuel vaporization process. To further validate the experimental findings, an analytical model revealing the volumetric radiation absorption distribution inside the liquid droplets, is explained.
William Barletta
USPAS, MIT
Abstract
Accelerators are essential to discoveries in fundamental physics, biology, and chemistry. Particle beam-based instruments in medicine, industry and national security form a multi-billion dollar per year industry. Yet only a handful of universities in the US offer any formal training in accelerator science. The United States Particle Accelerator School (USPAS) has developed a highly successful educational paradigm that, over the past twenty-years, has granted more university credit in accelerator / beam science and technology than any university in the world. Sessions are held twice annually, hosted by major US research universities that approve course credit, certify the USPAS faculty, and grant course credit. Educating the next generation of scientists and engineers to build and pilot the engines of discovery for accelerator-based science, medicine, and industrial production must remain a strong three-way partnership among universities, national accelerator laboratories and the USPAS. Each partner has an essential role that must be continually nurtured. The USPAS is proud of its role in the U.S. educational enterprise.
Charles Thangaraj
Fermilab
Abstract
The ability to manipulate the 6-D phase-space of the electron beam is important for both modern and future accelerators. One such phase-space manipulation scheme involves exchanging the longitudinal emittance with the transverse emittance of the beam. Coherent synchrotron radiation in the emittance exchange beamline could limit the performance of the emittance exchanger at short bunch lengths. In this talk, we present experimental and simulation studies of the coherent synchrotron radiation (CSR) in the emittance exchange line at the A0 photoinjector. We report on time-resolved CSR studies using a skew-quadrupole technique. We also demonstrate the advantages of running the EEX with an energy chirped beam.
Alexander Romanenko
Fermilab
Abstract
Superconducting radio frequency (SRF) cavities made of bulk niobium are currently used for particle acceleration in existing facilities such as SNS, CEBAF and CESR, and are a technology of choice for future machines such as Project X, XFEL, FRIB, NGLS, and ILC. Performance of such macrostructures as SRF cavities is almost entirely determined by a thin layer on the inner surface of about 40 nanometers thick. While the technology has matured to the point of reliably producing the quality factors of > 10^10 and larger than 35 MV/m accelerating gradients, the inner workings of most of the implemented "recipes" applied on the cavities (such as buffered chemical polishing, electropolishing, 120C baking, hydrofluoric acid rinsing) to achieve those remain unclear. Therefore the ways to improve cavity performance are not apparent. In this talk I will review my research targeted on filling this gap in knowledge as well as practical technological advantages coming from it.
John N. Corlett
Lawrence Berkeley National Laboratory
Abstract
LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one Megahertz. The CW superconducting linear accelerator is supplied by an injector based on a high-brightness, high-repetition-rate photocathode electron gun, prototyped in the APEX experiment under way at LBNL. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for different modes of operation, including self-seeded and external-laser-seeded, and each may produce high peak and average brightness x-rays with a flexible pulse format, and with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds. This talk will describe the design concept, recent developments in the design options and performance parameters, and progress in R&D activities.
Igor Meshkov
JINR Dubna
Abstract
The Nuclotron-based Ion Collider fAcility (NICA) project, a flagship project in high energy physics at JINR, is dedicated to
the construction of an accelerator facility that provides colliding beams for experimental studies of
1) hot and strongly interacting baryonic matter and a search for the mixed phase and critical endpoint in collisions of heavy ions,
and
2) spin physics experimental studies in collisions of polarized protons (deuterons).
The project is under development since 2007. A progress, status and plans of the project is presented.
The first program requires providing heavy ion collisions in the nucleon-nucleon center-of-mass energy range
of 4-11 GeV at an average luminosity of 1E27 cm^{-2}s^{-1} for Au(79+). The polarized beams mode is
proposed to be used in center-of-mass energy range of 12-27 GeV for pp and 4-13.8 GeV for
dd at a luminosity of more than or equal to 1E30 cm^{-2} s^{-1}. The key issue of the project is the
application of both stochastic and electron cooling methods in the NICA collider. The latter will be
used also in the NICA Booster for the preliminary formation of the ion beam.
The report contains a description of the facility scheme and characteristics of heavy ion operation mode,
the discussion of luminosity life time limitations, and recent results in the project development.
David Bruhwiler
Tech-X
Contributors: B.T. Schwartz, G.I. Bell and I. Pogorelov (Tech-X);
V.N. Litvinenko, G. Wang and Y. Hao (BNL);
S. Reiche (PSI)
Abstract
Increasing the luminosity of hadron beams in particle accelerators is critical for the advancement of nuclear and particle physics. Coherent electron cooling (CeC) promises to cool relativistic hadron beams significantly faster than alternative methods. We present simulations of 40 GeV/n Au+79 ions for a single pass through a CeC system, which consists of a modulator, a free-electron laser (FEL) amplifier and a kicker. In the modulator, the electron beam copropagates with the ion beam, which perturbs the electron beam density and velocity via anisotropic Debye shielding. Self-amplified spontaneous emission lasing in the FEL both amplifies and imparts wavelength-scale modulation on the electron beam perturbations. The modulated electric fields appropriately accelerate or decelerate the copropagating ions in the kicker. In analogy with stochastic cooling, these field strengths are crucial for estimating the effective drag force on the hadrons and, hence, the expected cooling time. The inherently 3D particle and field dynamics is modeled with the parallel VORPAL framework (modulator and kicker) and with GENESIS (amplifier), with careful coupling between codes. Treatment of realistic electron bunch distributions in the modulator requires careful use of the delta-f PIC algorithm in a regime where the algorithm has not been used before and no theory is available for code validation; hence, benchmarking of delta-f PIC with Vlasov/Poisson is underway for lower-dimensionality. Physical parameters are taken from the CeC proof-of-principle experiment that is under development at Brookhaven National Lab.
Timur Shaftan
Brookhaven National Laboratory
Abstract
The longitudinal motion of electron in a storage ring serves as an interesting example of a one-dimensional mechanical system. This system had been studied well many years ago and described in any accelerator textbook. On the other hand, this system is one of the simplest, like the hydrogen atom, or an electron in Paul and Penning electromagnetic traps. Detecting synchrotron radiation of a single particle enables a number of interesting studies on the particle's longitudinal state and motion in a giantic trap of the storage ring. I will discuss experiments with a single electron carried out at VEPP-3 storage ring at Budker Institute of Nuclear Physics in 1991-1993. In the first experiment we have measured the localization length of a single electron captured in the longitudinal potential well. In the second experiment we studied the stochastic process of the electron's synchrotron oscillations driven by random acts of the quanta emissions and radiation damping. In conclusion I will discuss some considerations for design of a storage ring, optimized for experiments with a single electron.
Charlie Briegel
Fermilab
Abstract
The Accelerator Control System at Fermilab has evolved to enable this relatively large control system to be encapsulated into a "box" such as a laptop. The goal was to provide a platform isolated from the "online" control system. This platform can be used internally for making major upgrades and modifications without impacting operations. It also provides a standalone environment for research and development including a turnkey control system for collaborators. Over time, the code base running on Scientific Linux has enabled all the salient features of the Fermilab's control system to be captured in an off-the-shelf laptop. The anticipated additional benefits of packaging the system include improved maintenance, reliability, documentation, and future enhancements.
Henryk Piekarz
Fermilab
Abstract
We propose to consider an alternative to the linac-only injector scheme for the Project X accelerator system. The alternative injector concept is based on the 1 GeV Pulsed Linac followed by an 8 GeV Superconducting Rapid Cycling Synchrotron (SRCS) and an 8 GeV Superconducting Dual Storage Ring (SDSR). The Pulsed Linac and the SRCS require new civil construction while the SDSR replaces the Recycler in the Main Injector tunnel. The proposed accelerator complex is not strongly technologically challenged and a very tentative cost analysis suggests a significantly lower cost than with the linac-only option while reasonably satisfying the beam intensity expectations for the Neutrino, Kaon and Muon physics as outlined for Project X. The saved funds would help construction of new neutrino experiments as well as solidify the R&D effort toward future high-energy physics accelerators.
Igor Rakhno and Leonid Vorobiev
Fermilab
Contributors: Alexander Drozhdin, Sergei Striganov (Fermilab)
Abstract
Stripping injection of negative hydrogen ions into the Fermilab recycler ring, combined with a beam phase painting technique, has been considered. The multiparticle 3D beam dynamics with space charge have been studied numerically, using STRUCT and ORBIT codes, for different painting scenarios. In order to achieve a uniform (quasi-KV) phase-space distribution and to reduce the foil heating, the following parameters were investigated: the number of turns, strengths and temporal forms of kicker magnets, and foil geometry. Performance of the stripping foil is a crucial parameter of the whole injection scheme, so that the latter has been designed to minimize the hit number on the foil. The temperature regime has been evaluated both semianalytically and numerically using Monte Carlo codes MARS and MCNPX, with radiation cooling and transport of delta-electrons taken into account. That all results agreed well proves the consistency of the models. It has been shown that the stripping foil can survive during injection with the parameters chosen for Project X at Fermilab.
Talks
in 2011
Michael Borland
Argonne National Laboratory
Abstract
With the Tevatron now shut down and slated for decommissioning, it is only natural to think about other possible uses for the 6.3-km tunnel. Given that the brightness of electron storage rings naively scales as radius cubed, one exciting possibility is to build a so-called ultimate storage ring light source. This talk describes a somewhat speculative exploration of this idea, showing the potential for a storage ring x-ray source of unprecedented brightness. In the process, we review the basic physics of storage ring light sources and describe computational approaches to their optimization.
Anna Mazzacane
INFN/FNAL
Abstract
A large scale effort is underway by the scientific community to design experiments at future linear colliders to complement the physics reach of the LHC. A new generation of detectors with unprecedented performance is required to be able to succeed in such an effort. Similarly, new simulation tools need to be implemented in order to design and optimize those detectors. I will present several physics and detector studies performed within the above environment, all of them implemented in an extremely powerful simulation framework, ILCroot, which I actively participated in developing.
Khalid Chouffani
Idaho State University
Abstract
Laser Compton scattering (LCS) experiments were carried out at the Idaho Accelerator Center (IAC) using the 5-44 MeV linear accelerator (LINAC). LCS X-rays were generated using a 50 ps electron beam colliding with a 4 GW, 250 ps, phase locked Nd:YAG laser. 60 Hz X-rays bursts resulting from an approximate head-on collision of relativistic electrons with the high peak power laser lines (1064, 532 and 266 nm) were generated with energies ranging from 20 to 122 keV. 122 keV LCS X-rays were used for X-ray fluorescence (XRF) experiments and X-ray transmission measurements in uranium samples of different concentrations. One of the purposes of this work was to use LCS X-rays as a non-invasive means for actinide elements identification and quantification in liquid samples. Results from our experiments showed that because of its relatively low spectral bandwidth, high linear polarization, energy tunability and low bremsstrahlung background (high signal to noise ratio), LCS is a useful x-ray source for hybrid k-edge densitometry (HKED). LCS X-rays with energies equal to 20 and 47 keV were generated using the laser fundamental wavelength and second harmonic respectively and were used for absorption based and phase contrast imaging experiments. Furthermore, because LCS photon beam properties such as photon energy and spectral bandwidth are strongly dependent on the electron beam parameters, LCS can also be used as a non-intercepting electron beam monitor for high power electrons beams.
Cesar Clavero
The College of William and Mary
Abstract
Superconducting thin films and multilayer coatings for superconducting radio-frequency (SRF) cavities in linear accelerators have greatly aroused the interest of researchers in the last years1. These coatings are expected to increase further the maximum field gradients that SRF cavities can withstand, pushing them above 100 MeV/m [2]. In this regard, Nb coated Cu cavities have been proposed as a prototypical system for this purpose since they combine the better thermal stability of Cu due to its much higher thermal conductivity and the superconducting properties of Nb thin films. Nevertheless, it is well know that structural dislocations and localized surface resistive defects on the thin films have a dramatically negative influence on their superconducting properties and resonator quality. I will present my investigations on the early stages of growth of Nb on Cu that established the foundations for achieving an optimum epitaxial growth of Nb thin films with optimum superconducting properties3. Also, multilayered coatings have been proposed to shield the peak electromagnetic fields in SRF cavities and to avoid vortex penetration2. This can be achieved by coating SRF cavities with multilayers consisting of alternating superconducting layers with higher critical fields (Bc) and dielectric layers. I will present my results on this topic and I will discuss the feasibility of this approach. Finally, I will show a glimpse of my investigations involving the interaction of electromagnetic radiation produced by accelerators and lasers with metallic and dielectric multilayers sustaining surface plasmon polaritons (SPPs).
1.H. Padamsee, Annual Review of Nuclear and Particle Science 43, 635 (1993).
2.A. Gurevich, Applied Physics Letters 88 (1), 012511 (2006).
3. C. Clavero, D. Beringer, W. M. Roach, J. R. Skuza, C. E. Reece, R. A. Lukaszew, “Strain effects on the superconducting properties of epitaxial Niobium thin films grown on sapphire”. Physical Review Special Topics Accelerators and Beams (PRST-AB) (2011).
Robert Hardin
Oak Ridge National Laboratory
Abstract
Simulation predictions and measurements of the SNS proton accumulator ring for the final design intensities indicate the existence of an electron-proton (e-p) instability. A feedback/damper system was designed to mitigate the e-p instability and experiments to determine the effectiveness of the prototype analog system have been performed. While damping has been achieved, supplemental Beam Transfer Function (BTF) measurements utilizing the feedback/damper system have also been conducted to ascertain the system limitations as well as for use as a standalone beam diagnostic. The feedback/damper system will be described, current damping results will be highlighted, and the BTF measurement will be described. A conclusion with the measurements of the SNS ring tune and chromaticity will be presented.
Alex Melnitchouk
University of Mississippi
Abstract
Silicon technology based particle detectors of the D0 detector, Silicon Microstrip Tracker (SMT) and Layer Zero detector, are introduced. Selected aspects of design, construction, testing, and performance are discussed. Procedures for quality control of fabricated detector elements and for mechanical assembly of the SMT barrel modules are outlined. Positioning tolerances are discussed. Physics of silicon detector operation at the microscopic level is reviewed. Effects of the radiation damage are discussed. Main components of the software chain of the Layer Zero detector, including Monte Carlo simulation, are highlighted. Selected Layer Zero detector tests at the assembly site (SiDet facility) and during commissioning are presented.
Sergiy Gladchenko
Laboratory for Physical Sciences
College Park, Maryland
Abstract
Superconducting resonators are measured at milliKelvin temperatures for photon detection and quantum computing purposes. We represent another important application of these devices. They are successfully used for study of the properties of crystalline and amorphous dielectrics in microwave diapason of electromagnetic fields. Current work combines several types of superconducting resonators and experimental methods providing the most complete number of experimental approaches for search and characterization of new materials which can be used for superconducting qubit fabrication. Experiments conducted at mK temperature range and input power varied from single photon regime to much higher numbers demonstrated that resonator loss behave in accordance with prediction for resonant contribution of two-level system (TLS) defects to dielectric function. Deviations from the standard model has been observed in several experiments and explained by increasing of importance of TLS-TLS interactions and size effects at certain experimental conditions.
Valeri Lebedev
Fermilab
Abstract
A proposal for a Project X based muon source is considered. The source creates a well collimated low energy muon beam with adjustable energy and time structure. The beam is a pure muon beam with extremely low pollution by other particles. It can be used as a muon source for the next generation mu-to-e experiment as well as for other experiments with stopped and/or small energy muons.
Yury Ivanyushenkov
Argonne National Laboratory
Abstract
Synchrotron light sources utilize special magnets – wigglers and undulators, to create high intensity photon beams
for a wide user community. Superconducting technology offers the possibility of creating undulators with
better performance than conventional hybrid or pure permanent magnet technologies.
An extensive program is underway at the Advanced Photon Source (APS) with the aim of developing
a technology capable of building superconducting planar undulators for APS users. During a two-year
R&D phase of the project we have built and successfully tested a number of short magnet prototypes.
This has led us to a conceptual design of the first full-scale undulator that is currently being built.
The APS upgrade program considers manufacture of three more superconducting devices. The status of the
project is presented.
The first APS devices are based on the NbTi superconductor. Better properties of the Nb3Sn
superconductor make it attractive for building short-period superconducting undulators.
Such devices are of interest not only to light sources but also to the FEL community.
A possible APS-FNAL collaboration on developing Nb3Sn undulators is suggested.
Stephen Webb
Stony Brook University
Abstract
Coherent Electron Cooling (CeC) is a promising new idea in cooling high intensity hadron beams in high energy colliders such as the proposed electron-ion colliders at BNL and Jefferson Lab, as well as the proposed LHeC upgrade at CERN. However, CeC requires a detailed understanding of the phase information in a free-electron laser. In this talk, I will briefly discuss intra-beam scattering as a motivation for CeC, existing analytical results, and present new results developed for my dissertation on FEL theory.
Tim Maxwell
Northern Illinois University
Abstract
Modern accelerators with sub-picosecond bunch duration place a new demand on the time resolution of bunch diagnostics. These include high-gradient laser-plasma wakefield accelerators, X-ray free electron lasers, and future linear colliders. This has motivated exploration of electro-optic sampling techniques with potential for femtosecond-scale, single-shot probing of diagnostic light such as coherent transition radiation or bunch wakefields. We present details on the installation of an electro-optic sampling experiment at Fermilab’s A0 photoinjector facility. Improvement of single-shot techniques by utilizing balanced, two-line imaging is described. Results on measurements of coherent transition radiation from short electron bunches are discussed. We conclude by suggesting a configuration for a time-resolved beam position monitor for measuring the spatio-temporal correlation within a single bunch.
Arun Saini
University of Delhi (India)
Abstract
Project-X is the proposed high intensity proton facility to be built at Fermilab. This facility is based on an H- superconducting linac which will be operated in continuous wave (CW) mode to accelerate the beam from 2.5 MeV to 3 GeV. The low energy section (2.5-160 MeV) uses three families of SC single spoke resonators i.e., SSR0, SSR1 & SSR2 which are operated at 325 MHz, and the high energy section (160 MeV-3.0 GeV) uses two families of 5-cell SC elliptical shape cavities which are designed for particles traveling at 61% and 90% of the speed of light. These are operated at 650 MHz. The operation in CW mode puts stringent tolerances on the beam line components, particularly in the low energy section. This presentation addresses operation requirements and design considerations for the CW linac and contains preliminary results of RF and beam optics optimization.
August 31, 2011 (Note special date/time/location: Wed.Aug.31 13:00 in the Huddle)
John T. M. Lyles
Los Alamos National Laboratory
Abstract
A prototype 201.25 MHz RF Power Amplifier for Los Alamos Neutron Science Center (LANSCE) has been designed, fabricated, and tested. The amplifier has exceeded our goal of producing 2 MW peak at 12% duty factor (240 kW of average power) at an elevation of 2.1 km above sea level. It has been designed to use a Thales TH628 Diacrode®, a state-of-art tetrode power tube that is double-ended, providing twice the power of a similar-sized conventional tetrode. The amplifier is designed with tunable input and output transmission line cavity circuits, a grid decoupling circuit, an adjustable output coupler, high-order mode suppressors, blocking, bypassing and decoupling capacitors, and a cooling system. The tube is connected in a full wavelength output resonator, with the lower main tuner situated ¾ of a wavelength from the central electron beam region in the tube and the upper slave tuner ¼ of a wavelength from the same point. The amplifier avoids use of a high-level anode modulator by leaving DC power on the tube, even between pulses. Field control for beam loading is handled by digital low level RF electronics, as the amplifier chain is linear. In addition to the ampifier, a new test facility was designed and constructed with a capacitor bank and charging power supply to supply up to 30 kV DC to the tube with 1500 uS RF pulses. A new fast protection/power monitoring system was developed to take samples of RF reflected power, anode HV, and various tube currents, with outputs to quench the HV charging supply, remove RF drive and disable the conduction bias pulse to the grid of the tube during fault events. The test stand is controlled with a programmable logic controller, for normal startup sequencing and timing, protection against loss of cooling, and operator GUI. A pair of production amplifiers are planned to be power-combined and installed for each of three DTL tanks at LANSCE to return operation to >10% duty factor.
Jingyu Tang
Chinese Academy of Sciences
Institute of High-Energy Physics, Beijing
Abstract
As part of the general effort to boost sustainable development of nuclear energy in China, with the support of the central government, the Chinese Academy of Sciences (CAS) has launched a long-term program of developing an accelerator-driven sub-critical reactor system (ADS). Three CAS institutes share the leadership of the major tasks. This talk will present the circumstances of boosting ADS studies in China, the roadmap of developing the China-ADS (or C-ADS), the organization of the R&D work, and design considerations for the driver linac. Some support conditions and previous work based at the Institute of High Energy Physics (IHEP) are also presented.
Denis Kostin
DESY
Abstract
The Cryo Module Test Bench (CMTB) at DESY is used since several years for the SRF module tests. Three XFEL prototypes modules, PXFEL1,2,3, were tested on this facility. A summary of the latest SRF module testing activities is presented. Module test infrastructure is described in detail. Progress and plans for the new XFEL testing facility, AMTF, are discussed. Module and cavity performance data for the XFEL prototype modules are presented.
Moses Chung
Handong Global University, Korea
Abstract
Future accelerators may need very special beam control and manipulation techniques to enable new scientific discoveries and many innovative applications. Gases and plasmas are quite useful mediums that can actively control and manipulate the properties of the beam. One good example is the gas-filled RF cavity for a future muon collider, which is being investigated in Fermilab. The gas-filled RF cavity can mitigate the RF breakdown problems in the presence of a strong magnetic field, and, at the same time, can provide a continuous energy absorber for ionization cooling. A possible liming factor of this cavity would be the beam loading effect from the accumulation of ionized electrons. A beam test has been prepared in the Mucool Test Area (MTA) to understand this loading effect and to find a solution to mitigate it. In this talk, an overview of the beam test will be given with a theoretical model for the beam loading effect.
Presentation
Veysel Demir
Northern Illinois University
Abstract
Recent developments in the design of graphic processing units (GPU's) have been occurring at a much greater pace than with central processor units (CPU's). The computation power due to the parallelism provided by the graphics cards got the attention of communities dealing with high performance scientific computing. The computational electromagnetics community as well has started to utilize the computational power of graphics cards for computing and, in particular, several implementations of finite-difference time-domain (FDTD) method have been developed. FDTD has been used to solve numerous types of problems arising while studying many applications, including the following applications: scattering, radar cross-section, microwave circuits, waveguides, fiber optics, antennas (radiation, impedance), propagation, medical applications, shielding, coupling, electromagnetic compatibility (EMC), electromagnetic pulse (EMP) protection, nonlinear and other special materials, geological applications, inverse scattering, and plasma. In this talk the basics of the FDTD method will be introduced, and an implementation of FDTD based on Compute Unified Device Architecture (CUDA) development environment from NVIDIA will be presented.
June 30, 2011 (Note special location: Curia II)
Marc Ross
Fermilab
Abstract
The ILC Technical Design Phase (TDP) is expected to finish late next year with the publication of the Technical Design Report. The goals of the TDP are to: 1) carry out the R & D studies to justify critical ILC reference design parameter choices, 2) update the technical design, 3) develop practical scenarios for globally-based mass production of high-technology components, and 4) produce a new cost estimate. This talk will describe the progress made toward these goals and will highlight the migration of high gradient SCRF technical expertise and competence within the three (Asia, Americas and Europe) ILC regions and associated industry. During the Technical Design Phase there has been excellent progress and regional SCRF capabilities have developed extensively - Fermilab's role in this success has been and remains quite important. In addition, beam test facilities to address collective effects (electron cloud), precision beam optics and high-gradient, high-beam -power superconducting linac operation have been constructed in each region and results from these will be a central part of the Technical Design Report and will be summarized in the talk. Design work on potential ILC sites and siting criteria will also be reported.
Amit Lal
SonicMEMS Laboratory, Cornell University
Abstract
This talk will present recent results on microfabricated lateral electric field guides for guiding and accelerating argon ion beams. The scaling of gaps using lithography favors the use of electric fields to guide charged particles, instead of magnetic fields. This scaling, coupled with high frequency integrated electronics, can potentially eliminate the need for permanent magnets enabling ultra miniaturized high energy beam sources. Ar+ ions of ~2keV are shown to be guided and bent along a curved path to realize a 90° turn, in silicon micro-fabricated channels of radius 1-mm and 2mm respectively and on printed circuit boards of 4-mm radius. The lateral field guides can be used to guide charged particles for energy analysis or acceleration. Chip-scale ion acceleration and deceleration, of up to 30eV, is also demonstrated with the use of longitudinal electrical fields. These results pave the way for further integration of accelerator miniaturization for reducing the size of SEMs, gas analyzers, and x-ray sources.
Presentation
June 21, 2011 (Note special time and location: 11:00 in Curia II)
Thorsten Kuerzeder
Technical University Darmstadt (Germany)
Abstract
Since 1991 the superconducting Darmstadt linear accelerator S-DALINAC provides an electron beam of up to 130 MeV for nuclear and astrophysical experiments. The accelerator consists of an injector and four main linac cryostats, where the superconducting cavities are operated in a liquid helium bath at 2 K. Currently, the injector delivers beams of up to 10 MeV with a current of up to 60 microamperes. The upgrade aims to increase both parameters, the energy to 14 MeV and the current to 150 microamperes. Because of an increase in RF power to 2 kW, the old coaxial RF input couplers, being designed for a maximum power of 500 W, have to be replaced by new waveguide couplers. Consequently, modifications to the cryostat-module became necessary. The talk will review the design principles, the necessary changes in the RF components and srf cavity production.
Yuri Kamyshkov
University of Tennessee
Abstract
Production of very cold and ultracold neutrons can be significantly increased in a dedicated spallation target with 4pi cryogenic moderation coverage and with use of high-m reflection mirrors. Such a target with power < 1 MW can be fed with ~ 1 GeV beam from the Project X linac or can be used in combination with compact superconducting cyclotrons discussed by the DAEdALUS Collaboration. Such a cold neutron source will open new experimental possibilities to search for appearance transformation of neutrons to antineutrons and for disappearance of neutrons to sterile mirror neutrons; the latter can be one of the components of the dark matter world. Experiments for observation of transformation of very slow neutrons should best be performed with a vertical neutron beam that will minimize the devastating effects of gravity. Such experiments can be planned for the Project X neutron target and for very long vertical experiment in the mine shafts such as one that exists in Homestake mine. Optimization of the performance of the cold spallation source should be done in combination with sensitivity and layout optimization of the realistic neutron oscillation search experiment.
Kazuhito Ohmi
KEK
Abstract
Electron cloud effects have been studied in many machines, both positron and proton ones. The characteristics of electron cloud build-up and instability depend on the machine: positron or proton, short or long bunch length, low emittance or not. This talk is dedicated to the instability simulation and measurements to which the speaker contributed, mainly for J-PARC, (Super)KEKB, and ILC damping rings.
Alex Melnitchouk
University of Mississippi
Abstract
Measurements of the W boson mass and width with the D0 detector are presented with a focus on published results with integrated luminosity of 1fb-1. Impact of the W boson mass measurement on constraining the Standard Model, analysis strategy, experimental techniques, and primary sources of uncertainties are discussed. Selected aspects of the current work in progress on the 5fb-1 measurement at D0 are highlighted. Prospects of the W boson mass measurement with the full Tevatron dataset and its physics implications are discussed.
Santosh Jangam
Indian Institute of Technology, Kharagpur
Abstract
Large projects based on applied superconductivity, such as particle accelerators or fusion devices like tokomaks require complex helium systems. Helium is used in refrigeration mode for cooling of RF cavities and superconducting magnets in Particle Accelerators. The two phase flow is always encountered in cryogenic process due to heat inleak. The large variation in viscosity, heat capacity and thermal conductivity are of much importance for using helium as refrigeration media in single phase. The evaluation of the system considering these non- homogeneous transport phenomena, superfluidity and supercritical zone is necessary to validate the performance with respect to design parameters such as pressure drop, heat load and loss in refrigeration capacity. A versatile and efficient cryogen distribution system has been designed and fabricated to deliver both liquid helium and liquid nitrogen to the cryostats in LINAC. The two-phase helium at 4.5 K produced at the JT stage in the Linde TCF50s refrigerator is delivered to the cryostats through a cryogen distribution system. The cryogenic processes are considered to be a special niche in process simulation. Simulation of the refrigerator has been performed using Aspen Hysys®. Some specific customizations are required to cope with cryogenic applications. Steady state simulation is used for design and rating purpose of the Helium systems. This analysis helps us to suggest rectification in existing refrigeration system and any modification if required in cryogen distribution system. Dynamic simulation is a tool to analyze the system in transient modes. The disturbances and fluctuations such as heat inleak, pulsed load and surges are modelled using dynamic simulation. The frictional pressure drop calculations give estimate of the loss in the refrigeration capacity due to the helium fluid flow in the system. The control parameter values for pressure, temperature and valve opening to achieve equal flow in each cryostat are calculated. The standalone heat load calculations were done to estimate the theoretical values using heat and mass transfer principles.
Charlie Reece
Jefferson Lab
Abstract
The CEBAF 12 GeV Upgrade project requires 80 new 7-cell SRF cavities incorporated into 10 new CW cryomodules providing >100 MV each. The full complement of cavities has been delivered. A streamlined production process has been implemented to turn these into qualified 8-cavity strings. Although not strictly required to meet project requirements, light electropolishing of these cavities has become standard and yields consistent performance exceeding requirements, often equivalent to ILC aspirations. The applied process will be described and the performance testing results summarized to date. JLab also has a major construction project underway which will fully renovate all SRF research, fabrication, processing, cleanroom, and assembly facilities. This “Technology and Engineering Development Facility” (TEDF) Project was launched in 2010 and will run through 2012. The majority of the SRF facilities will be consolidated in a new building with 30,000 square feet (3300 square meters) of workspace attached to the existing Test Lab. This purpose-built facility integrates fabrication, chemistry, and cleanroom suites and cryomodule assembly lines for convenient, yet flexible operations serving multiple DOE projects in parallel. The facility plans and progress status will be presented.
May 24, 2011 (Note special time: 11:00 in 1-West)
Chan Joshi
University of California at Los Angeles
Abstract
Plasma Wakefield Acceleration has demonstrated impressive progress in the last ten years. Acceleration gradients of 50 GeV/m have been sustained in meter-scale plasma to double the energy of initially 42 GeV electrons from the SLAC linac in a landmark experiment. A straw man multi-stage design of a 1 TeV CM e+e- collider based on the PWFA concept has been introduced which specifies the parameters for the drive and the accelerated beams. The next phase of this research will focus on achieving many of the requirements of a single stage of a multi-stage PWFA-based collider. These include the necessary charge, energy spread, energy extraction efficiency and emittance preservation. This is the purpose of the FACET facility now under construction at SLAC. Researchers are beginning to consider the possibility of using ultra-relativistic proton drive bunches to accelerate electrons as well to perhaps go beyond 1 TeV. I will discuss these exciting developments in this talk.
Alexey Burov and C.Y. Tan
Fermilab
Abstract
Longitudinal instabilities observed at Tevatron, RHIC and SPS can be explained as loss of Landau damping (LLD), which is shown to happen at that low impedance as at the Tevatron. For repulsive wakes and single-harmonic RF, LLD is found to be extremely sensitive to steepness of the bunch distribution function at small amplitudes. Based on that, it was theoretically predicted that the oscillations can be stabilized by means of small bucket shaking. Dedicated measurements in Tevatron have shown that this method does stop the dancing.
Tom Schwarz
University of California at Davis
Abstract
In elementary particle physics, symmetry is fundamental to the theories we use to describe the world in which we live. A discrepancy in a symmetry predicted by the standard model can perhaps point to new types of physics, to an anomaly in the data, or it can demonstrate that current theories need revision. Since 2006, scientists at CDF and D0 have been studying the forward backward asymmetry in top quark pair production as a test of discrete symmetries of the strong interaction. I will discuss recent results which indicate that this production asymmetry is larger than expected by the standard model, and that the asymmetry is dependent on the mass of the top antitop system.
Presentation
Richard Wade
Science and Technology Facilities Coucil (UK)
Abstract
Following several years of sustained growth in funding, UK researchers faced
the dual challenges of an economic downturn and a change of government.
STFC, the primary funding source for High Energy Physics, has fared better
than many agencies but challenges remain and the agenda has changed.
In this talk I will outline the changing landscape of research funding in the
UK, summarise the activities covered by STFC and describe our strategy and
priorities for HEP as we look forward to results from the LHC later this year.
Daniel Mihalcea
Northern Illinois University
Abstract
Wakefields generated by a drive electron beam passing through a dielectric-loaded waveguide can be used to accelerate a closely following witness beam. Recently measured wakefield gradients are at 100 MV/m level (Argonne Wakefield Accelerator). A brief theoretical introduction to this acceleration technique is presented as well as the status of the research. Recent results show that "beam tailoring" plays an important role in increasing the amplitude of the wakefields and the efficiency of the energy transfer. A special attention in this talk is given to wakefields produced by flat beams in slab-symmetric structures. The prospectives for achieving ultra-high accelerating field gradients (> 1 GV/m) are examined.
Anna Grassellino
TRIUMF
Abstract
One of the outstanding scientific issues related to superconducting radio frequency cavities made of high-purity bulk niobium is the occurrence of field dependent losses in the walls of the niobium cavity. These losses occur at different RF field levels, in medium and high field range, and therefore pose severe limitations to the niobium technology for both CW or pulsed applications – where the final goal is, respectively, maximizing Q and pushing to highest possible gradients. In this presentation I will summarize my PhD thesis work which focused on understanding causes and mechanisms behind losses at both medium (magnetic peak surface field 20-80mT) and high field (above 80-100mT) regime. The problem was studied using different approaches: top-down – designing and implementing several cavity test experiments – or bottom-up – utilizing the unique TRIUMF muon spin rotation (muSR) facility to investigate niobium properties on a microscopic level. The cavity tests were performed on both low frequency and high frequency niobium cavities, which gives the advantage of learning how frequency or different typical treatments might play a role in the field dependent wall losses. The muon spin rotation experiments were conducted on high field Q-slope cutouts from small and large grain BCP (buffered chemical polished) 1.5GHz cavities. The experiments and results obtained will be presented, and it will be discussed in which future direction those results lead.
Presentation
Marc Buehler
University of Virginia
Abstract
The Higgs mechanism accommodates the observed breaking of electroweak symmetry in the standard model. In addition to generating masses for the electroweak W and Z bosons, as well as for fermions, the theory predicts a new scalar Higgs boson with well-determined couplings, but unknown mass. Confirmation of the existence and properties of the Higgs boson would be a key step in elucidating the origins of electroweak symmetry breaking. In this talk I will introduce the DZero detector focusing on the trigger system and related challenges at high instantaneous luminosities. I will discuss the search for a high mass standard model Higgs boson in the channel where the Higgs boson is produced through the fusion of two gluons or two electroweak bosons, with subsequent decay H->WW->lvqq. I will also present the latest Tevatron Higgs combination results. Finally, I will discuss possibilities for Higgs boson searches and measurements at a future Muon Collider.
Edward Nissen
Northern Illinois University
Abstract
As the importance of beam intensity increases within the accelerator physics world, new methods of modeling intense beams will become equally important. The methods presented here have been developed to model space charge in the University of Maryland Electron Ring, which uses low energy electrons as proxies for high energy ions in order to study space charge. The work was performed using the computer code COSY Infinity 9.0 which uses differential algebras to determine high order, exact, numerical derivatives. The tools developed here go beyond merely tracking particles through the ring, including the geometry of the injection line, the effects of the Earth’s magnetic field, and the effects of space charge on the transfer map of the system. Using this map, quantities of interest such as tunes or chromaticities can be extracted directly using normal form methods. This method of adding space charge to the map of the system uses a novel Poisson solver that is massively parallelizeable and scales linearly with particle number. Additionally, an implementation of the fast multipole method has been included. The calculations that have resulted from this model are also compared to experimental data taken on the ring itself. These methods have been implemented in two dimensions; once they have been adapted to three they will improve the modeling of particle beams at the intensity frontier.
Presentation
Zhijun Chen
Argonne National Laboratory
Abstract
Since the 1987 discovery of the high temperature superconducting (HTS) YBa2Cu3O7-x (YBCO) material, it has held the promise of zero-resistance devices operating at extremely high currents while using inexpensive liquid-nitrogen as a cryogen. And that’s exactly what this promising cuprate superconductor has become after two decades of extensive development. But it was not until recent years that YBCO became attractive to superconducting magnet applications, an area which has long been comfortably dominated by Nb-Ti and Nb3Sn. The transition is both pushed by materials property enhancement and pulled by the need for extremely high field magnets, e.g., the 30-50 T solenoids to be used in a Muon collider, an application domain far beyond the capability of Nb superconductors. Yet for YBCO, entering the new territory of application at 4.2 K leaves many well-resolved issues at 77 K again largely unknown, as the requirements to optimize YBCO are highly temperature and field dependent. In particular, dealing with both the poor grain boundary transport and the strong anisotropy of tape-form YBCO poses tough scientific and manufacturing challenges. This talk will summarize our knowledge on how to tune the materials properties of YBCO to the greatest extent possible to suit magnet needs, and how to develop appropriate strategies for dealing with complexities in using this material for high field magnet applications.
Presentation
Jeffri Narendra
Michigan State University
Abstract
Microwave plasma sources of dimensions less than a size of a few millimeters have possible
applications as miniature materials processing sources for use in spatially localized deposition
applications, deposition and surface treatment on the inside of larger work pieces, formation
of arrays of small plasmas for simultaneous processing of localized regions across large areas,
portable-low temperature sterilization, incorporation of plasmas in micro-systems for chemical
analysis, microreactors, surface treatment, and micro-thrusters for spacecraft propulsion.
Accordingly, this investigation is devoted to the design and development of very small microwave
plasmas for localized surface treatment.
Two designs of microwave generated microplasma applicators will be presented. The first
applicator is based on a microstrip transmission line, and the second one is based on
a coaxial cavity. The discharge is created by using 2.45 GHz microwave energy and the
diameter of the plasma stream considered in this study ranges from 2 millimeters down to
10’s microns. the microwave power utilized ranges from a few Watts to 100 Watts and
the operating pressures range from 0.5 Torr up to an atmospheric pressure.
Several diagnostic techniques were utilized to characterize the miniature discharges.
Gas temperature and electron density analysis was performed using optical emission
spectroscopy (OES). The electron temperature and electron density measurements
were performed using the double Langmuir probe (DLP). The power densities for argon
discharges created by these applicators vary from 10's to over 800 W/cm^3 and the plasma
densities are are in the range of 1E12 to over 1E14 /cm^3 depending on the pressure, power,
and feed gas composition.
An argon/SF6 and an argon/oxygen feed gas mixtures are used to create a plasma stream
with radicals for silicon etching and polycrystalline diamond etching respectively.
Experimental results for these etching procedures will also be presented.
Presentation
Alex Rak
Bradley University
Abstract
Many products used to detect and locate sources of radiation are in existence today. The problem with most of these is that they are inaccurate or very bulky. The two systems that I will be describing were developed to help solve these problems. The first is a portable system that can be setup in the field and uses a small NaI scintillator to determine the location of the radiation. It uses motors to move the scintillator in and out of a lead cylinder, where it records the incident radiation. By applying statistics to the recorded values, a MATLAB program can determine an approximate location to the source of radiation. The second system is less portable but much more accurate. The increase in accuracy is achieved by swapping the scintillator for a gamma camera. The camera uses a large thin sheet of NaI scintillation crystal, which increases the amount of radiation that can be measured in a given time. A small lead bar is suspended in front of the camera, which blocks some of the incident radiation. This introduces what looks like a shadow when the data is interpreted. A Wolfram Mathematica program turns the matrix of millions of values into a smaller set of position coordinates. These positions are then brought into MATLAB as an image. A MATLAB code then cleans up the image and uses a technique known as Hough Transform to find the edges of the shadow. These edges are then used to find the trajectory of the source location.
Presentation
Mauro Munerato
University of Ferrara, Italy
Abstract
SuperB is one of the flagship projects of the Italian Government and in 2010 has been approved. Starting from the Conceptual Design Report (CDR), now the collaboration is moving to the Technical Design Report (TDR). SuperB will be an asymmetric e+e- collider with a detector that can be able to find some signals from new physics. This talk will be mainly focused on the design studies of the muon detector for this experiment: the detector will be substantially composed of three optical fibers within a scintillator bar that will carry out the signal to silicon photo multipliers (SiPM). Starting from Monte Carlo simulations (performed by a package developed by the SuperB collaboration and based on GEANT4) and from the CDR proposal, I try to find the best design in order to have a detector with high efficiency and good muon identification. In particular, in this talk all analyses conducted during my Ph. D. will be presented. In this work a solution to silicon damage due to neutron rate has been proposed in order to preserve the silicon photo multipliers from high rate. A first analysis of the beam test data collected during the beam test at Fermilab, indicates that the prototype works well and meets the required specifications.
Presentation
Marcel Stanitzki
STFC Rutherford Appleton Laboratory
Abstract
The proposed linear colliders like ILC and CLIC bring a complete new set of challenges for their design. In order to achieve the required precision for the physics, new approaches are necessary. I'll give an overview of these approaches and then review the underpinning technologies and their current R&D status. The machine design choices have a big impact on the detectors, from beam backgrounds, to timings and last the choice of the run plans sharing a single interaction region. Finally I give an outlook on the current developments and the next steps in the linear collider program.
Dan Berkovits
Soreq Nuclear Research Center, Israel
Abstract
Phase I of the Soreq Applied Research Accelerator Facility - SARAF, has been installed and is currently being commissioned at Soreq NRC. SARAF Phase-I linac is designed to accelerate 2 mA proton and deuteron beams at energies up to 5 MeV. The status of the main Phase I components and beam commissioning results will be discussed.
Sebastian Carron
Fermilab
Abstract
I will describe our efforts at CDF to maintain and operate an aging silicon detector, and to search for the Standard Model Higgs Boson, in particular in the H->WW decay channel. This will be presented in the context of the attempt to extend the operations of the Tevatron for three additional years, which will not be carried out due to lack of additional funding. A lost opportunity, an elusive particle and a "miraculous" detector.
Presentation
Alexander Mikhailichenko
Cornell University
Abstract
Polarized positrons together with polarized electrons deliver the most pure initial conditions
for the electron-positron interactions at ILC, which makes experiments with polarized e+e– more valuable.
The rate of positron production required for ILC is ~3.9E14 e+/sec
(2E10·e+/bunch 2625 bunches·5 Hz rep rate; with 50% overhead) demanding a source of positrons
which is challenging, as traditional methods of positron production from the electrons are hardly realizable
for the positron rate required.
The method of positron production accepted as a baseline for ILC is a two-stage process. At the first stage,
the circularly polarized photons are generated in the magnetic field of a helical undulator having a period of
~1 cm. The primary ~100 GeV electron (or positron) beam, appointed for this purpose, generates a burst
of photons with energy ~10-20 MeV and polarization >80%. At the second stage, these gammas are converted
into positrons and electrons in a thin (~0.4Xo) target. Longitudinal polarization is transferred from the gamma-beam
to the secondary particles in accordance with their energy.
A metallic (Ti) rim is used as a conversion target for the gammas in the ILC baseline design. It is ~1-m in
diameter and is spinning with ~1/50s.
The effectiveness of an Optical Matching Device (OMD), located right after the conversion target plays a key
role in all instances involved in the conversion system, such as the length of the undulator, its field strength
(defined by its K-factor) and the thermal load in the target. Stray magnetic field induction in a spinning target rim by
OMD should be minimal; otherwise, it destroys the emittance and adds to the target heating. The accelerating
structure located right after the OMD is challenging also. It should operate in focusing solenoidal fields at a maximal
accelerating gradient.
An OMD with a lithium lens as a key element of collection optics satisfies all demands. This lithium lens is
a tiny copy of the lithium lens used for antiproton collection at FERMILAB, but working with liquid lithium.
We will describe the method of calculation of positron efficiency with a lithium lens, the liquid lithium lens design,
undulator design and design of the primary accelerating RF structure that is located right behind the lithium lens.
The undulator-based positron source is able to deliver polarization ~35% with a ~20m-long undulator.
The polarization increases to ~70% after the source is upgraded to an undulator length ~170 m and K~0.45, with
average efficiency ~1.5 positrons per initial electron (i.e., 50% overhead). As the OMD with lithium lens is extremely
effective, it allows usage of tungsten as a target material, delivering an additional ~25% to the efficiency of positron generation.
In the E-166 experiment, performed at SLAC recently, an effective positron polarization of ~80% was achieved
with a 1-m long undulator having a period of 2.54 mm and K~0.17 and a tungsten target 0.2Xo-thick.
Presentation
Talks
in 2010
Hengjie Ma
Brookhaven National Laboratory
Abstract
Large-scale accelerators like those in the Spallation Neutron Source (SNS) and National Synchrotron Light Source - II (NSLS-II) require that the low-level RF systems not only deliver the required control performance, but also have the necessary features that provide the operability and usability in their large systems. The performance and versatility of today's digital LLRF well suits both requirements. The successful commissioning and operation of SNS LLRF has demonstrated the capabilities of digital LLRF, and this experience is benefiting the further development for the future NSLS-II accelerators.
Presentation
Diktys Stratakis
UCLA
Abstract
Normal conducting accelerator rf structures in the frequency range of 201 MHz to 805 MHz have been found to experience damage and drop of their maximum achievable gradient due to breakdown when operated within multi-Tesla magnetic fields. Better understanding of these issues is desirable for the development of structure designs and processing techniques that could improve the performance of muon cooling lattices which require both high gradient rf and strong magnetic fields. Here, a model is proposed and simulated, for a possible trigger of rf breakdown in magnetic fields based primarily on field-emission from microscopic surface roughnesses. Our results are compared against experimental data for an 805 MHz cavity. Possible solutions to these problems are discussed, including designs for magnetically insulated rf in which the cavity walls are chosen to be parallel to magnetic field contour lines and consequently damage from field emission is expected to be suppressed. Experiments that could further study the behavior of rf cavities in magnetic fields are outlined.
Bill Pellico
Fermilab
Abstract
Conceived in February 2010 and established in April 2010, the Proton Task Force was created to assess the outlook of operating the Proton Source for the next 15 years. The task force produced a report to management in September that outlined what they had found and possible solutions to areas of concern.
Lawrence Deacon
University of London, Royal Holloway
Abstract
Muon flux estimates into the CLIC detector are produced via the simulation of halo generation due to beam gas scattering and interaction of particles with machine components. The possibility to reduce the muon flux into the detector region using magnetized shielding is discussed and possible shielding systems are presented.
Presentation
Shigeki Kato
KEK
Abstract
Niobium electropolishing (EP) for superconducting RF (SRF) cavities is
generally considered to be the best technology today. However, the hydrofluoric
and sulfuric acid mixtures usually used in the EP process are harmful and require
carefully controlled handling and many additional facilities. Recently we have
proposed a new application of electrochemical buffing (ECB) to niobium SRF cavities.
In the method of ECB, a rotating disk with abrasive fine particles is pressed
against a sample surface in the presence of an electrolyte. The disk and the
sample function as a cathode and an anode, respectively, and an aqueous solution
of sodium nitrate is used for the electrolyte. This technology brings us a couple
of remarkable advantages like high etching rate, ultra low surface roughness,
cost-effectiveness and environmentally-compatible polishing. The electrolyte in
particular allows us to be released from many constraints of niobium surface
polishing with the EP method, for instance, the electrolyte ages very slowly,
no heat exchanger is required, no special protective materials for the facility
against the strong acid are required, no chemical hood is required, no alarm and
safety systems are required, and no safety zone and safety wear are required.
In the talk, the principle of ECB, a comparison of ECB with EP, the results of
surface analyses, and the application of ECB to niobium SRF cavities will be introduced.
Hisham Kamal Sayed
Old Dominion University / Jefferson Lab
Abstract
A high luminosity polarized electron-ion collider (MEIC) is envisioned as
the primary future of the Jefferson Lab nuclear science program beyond the
12 GeV upgraded CEBAF. The present conceptual design of MEIC selects a
ring-ring collider option and covers a CM energy range up to 51 GeV for
both polarized light ions and un-polarized heavy ions. The electron-ion
collider (ELIC) at Jefferson Lab is mainly composed of two figure-of-eight
rings, intersecting at up to four collision points, with a proton energy of
30-225 GeV (30-100 GeV/A for ions up to Pb) and electrons (and positrons)
from 3 to 9 GeV, with a design luminosity approaching 10^34cm^(-2)sec^(-1) and
compatible with simultaneous operation of the 12 GeV CEBAF for fixed-target
experiments. Figure-8 collider ring is adopted for preserving ion beam
polarization during acceleration and also accommodation of a polarized
deuteron beam for collisions.
Progress in the conceptual design and optimization of major components
including electron collider ring, an interaction region with chromaticity
correction, and spin rotators will be discussed.
Roger Dixon
Fermilab
Note Location: Curia II
Abstract
Accomplishments, programs, projects and issues will be summarized. Talk will be given in 4 dimensions, but projected onto a two-dimensional space for those who think better in 2 dimensions. 1-dimensional thinkers will be asked to form a single file line in the back.
Sang-ho Kim
Oak Ridge National Laboratory
Abstract
The SNS Superconducting Linac (SCL) has been reliably providing a main acceleration for neutron production since 2006. The use of superconducting elliptical cavities for particles whose velocity are less than speed of light (beta< 1), make this accelerator a very important milestone for learning operating conditions of this type of cavities. Since the SNS SCL is the first large-scale high-energy pulsed superconducting proton linac that provides high beam power utilizing H- beams, many aspects of its performance and reliability were unknown and unpredictable during the design and commissioning periods. A large amount of data has been collected on the behavior of cavities and cryomodules in various conditions. This experience will be of great value in determining future optimizations of SNS as well in guiding in the design and operation of future superconducting linacs. Overview and lessons learned of the SNS SCL including design concerns, performance, path forward for the SNS power ramp-up goal, and upgrade path of the SNS superconducting linac, will be presented.
Vladimir Shiltsev
Fermilab
Abstract
I will give a general introduction to the types of ground motion phenomena, describe the instruments used to study them and discuss major effects on the operation of accelerators. It will be shown that tolerances on alignment and stability of the elements of high energy frontier colliders are getting tighter and tighter. Many measurements at the accelerator facilities carried out over the past 2 decades reveal an interesting feature of natural ground motion - it has a component that looks like Brownian motion (random walk) both in time and in space. As explained in the recent article Shiltsev, PRL 104, 238501 (2010), that observation points to a fractal nature of the ground.
Walter Hartung
Michigan State University
Abstract
A program of research and development in superconducting radio-frequency cavities at Michigan State University (MSU) began in the year 2000. The primary goal was to support the design and construction of a next-generation superconducting linac for nuclear physics research. In December 2008, MSU was selected by the Department of Energy to host the Facility for Rare Isotope Beams (FRIB). FRIB is being designed to produce beams of ions at 200 MeV per nucleon with 400 kW of beam power. This requires an 850 MV superconducting linac. Quarter-wave and half-wave resonators will accelerate the beam; a total of about 350 resonators will be required. FRIB will produce radioactive ions via particle fragmentation at a significantly higher rate than is presently possible at MSU's National Superconducting Cyclotron Laboratory, allowing for new discoveries about the properties of nuclei. This talk will provide an introduction to the FRIB project, the FRIB driver linac, and the FRIB re-accelerator linac. The development program for the FRIB resonators will be described.
Mingqi Ge
Fermilab
Abstract
Surface defects such as pits, bumps, cracks, scratches, etc., have been identified as some of the main sources of limitations to SRF cavities, causing a significant spread in cavity gradient. Several new techniques for surface defects research have been developed at Fermilab. The surface replica technique can provide 1 micron resolution and depicts a vivid 3D shape of defects as well as a wealth of topology information. This information allows us to establish the mechanism of local electromagnetic quench at the flaws. The replica procedure was proved to be harmless to high performance cavities. Fermilab’s laser re-melting system is aimed at removing the flaws that limit cavity RF performance to below 20MV/m. We succeeded in re-melting a pit in a 1.3GHz single-cell cavity, and after just a light electropolishing we restored the gradient to 40MV/m. Using a laser welding technique to fabricate SRF cavities dramatically reduces the equator weld heat-affected zone area in comparison with the standard electron beam welding technique. The potential benefit is to decrease the probability of pit generation in the equator region.
Shekhar Mishra
Fermilab
Note Location: Curia II
Abstract
[no abstract]
Young-Min Shin
University of California at Davis
Note Location: Curia II
Abstract
Controlling and manipulating electricity/magnetism and electrodynamics has been the most intriguing subject as it plays an integral role in the innovation of scientific and technological paradigms that have profound impacts on how people live and work. Electromagnetic waves can be readily converted to and from any type of usable energy and can carry informative data signals. Also, they visualize micro/macroscopic features, see through opaque substances, and analyze chemical and biological components. However, naturally existing materials do not fully support the realization of all these promising potentials due to fundamental physical limitations of classical electromagnetism based on right-handed (positive-index) convention. During the past few years, scientists have thus paid a great deal of attention to artificially engineered EM materials, Metamaterials, as they have explored physical properties which can be the breakthrough to jump over the insurmountable obstacle conventional electromagnetic theories confront. Metamaterials are designed to pursue extraordinary optical natures, difficult or impossible to exist in natural materials or chemical compounds. While they have been widely studied in optics and material engineering, application to plasma and accelerator physics has been rarely investigated. This research extends the scope of the topic to near-/far-field interaction and RF radiation dynamics of electron beam in the metamaterials in the microwave and THz regimes for omnidirectional and/or unidirectional EM wave beaming and routing applications such as accelerator, plasma diagnostics, bio-medical imaging, radiology/oncology, radiometry, and active denial.
Presentation
Alan Krisch
University of Michigan
Note Location: Curia II
Abstract
There will be a review of the history of polarized proton beams, and a discussion of the unexpected and still unexplained large transverse spin effects found in several high energy elastic and inelastic proton-proton spin experiments at the ZGS, AGS, Fermilab and RHIC during the past 4 decades. Next, there will be a brief discussion of possible future polarized proton beams and their possible experiments including polarized Drell-Yan experiments and the violent elastic collisions of polarized protons at Fermilab’s high intensity 120-150 GeV Main Injector.
Alexey Burov
Fermilab
Abstract
General theory of beam transverse oscillations is discussed for coasting and bunched beams. Main issues include the mode structure, growth rates and Landau damping. Special attention is paid to a role of space charge.
Lucio Rossi
CERN
Abstract
No abstract
Alexey Burov
Fermilab
Abstract
Originally, Landau found a decay of oscillations in collisionless plasma, solving Vlasov equation with Laplace transform (1946). Later, Bohm and Gross pointed out that Landau damping results from energy transfer from the oscillating coherent field to its resonant particles (1949). The third point of view on the Landau damping was developed by van Kampen, who built a theory of eigenfunctions of the Vlasov equation (1955). In this talk, all the three approaches are discussed for longitudinal oscillations of a coasting beam.
Hamid Aït Abderrahim
Belgian Nuclear Research Centre
Abstract
The MYRRHA project started in 1998 by SCK•CEN in collaboration with Ion Beam Applications (IBA, Louvain-la-Neuve), as an upgrade of the ADONIS project. MYRRHA is designed as a multi-purpose irradiation facility in order to support research programmes on fission and fusion reactor structural materials and nuclear fuel development. Applications of these are found in ADS systems and in present generation as well as in next generation critical reactors. The first objective of MYRRHA however, will be to demonstrate on one hand the ADS concept at a reasonable power level and on the other hand the technological feasibility of transmutation of Minor Actinides (MA) and Long-Lived Fission Products (LLFP) arising from the reprocessing of radioactive waste. MYRRHA will also help the development of the Pb-alloys technology needed for the LFR (Lead Fast Reactor) Gen.IV concept.
Transmutation of MA can be completed in an efficient way in fast neutron spectrum facilities. Both critical reactors and sub-critical Accelerator Driven Systems (ADS) are potential candidates as dedicated transmutation systems. However, critical reactors, heavily loaded with fuel containing large amounts of MA, pose safety problems caused by unfavorable reactivity coefficients and small delayed neutron fraction. A sub-critical ADS operates in a flexible and safe manner even with a core loading containing a high amount of MA leading to a high transmutation rate. Thus, the sub-criticality is not a virtue but rather necessity for an efficient and economical burning of the MA. Besides the reduction of the HLW burden, the MYRRHA project will serve the purpose of developing the lead alloys technology as a reactor coolant that can be used one of the Generation IV reactor concepts namely the Lead Fast Reactor (LFR).
Although carrying out the MYRRHA project will lead to the demonstration of the efficient and safe transmutation of MA in ADS systems as the ultimate goal the implementation of such a project will in addition trigger the development of various innovative technologies and techniques that are of interest for various nuclear fission and fusion applications. These include :
Zachary Conway
Cornell University
Abstract
Almost all superconducting-niobium accelerator cavities have surface defects and have to be operated at
accelerating gradients below the maximum theoretical limit. This increases the cost and complexity of
several proposed accelerator facilities, e.g., the International Linear Collider (ILC), the FNAL project-X
driver accelerator, and other high-accelerating gradient machines.
Surface defects nucleate normal conducting regions which become unstable and expand once the
conductive cooling to the defect is less than the dissipated RF power. This presentation will begin
with a review of current state-of-the-art niobium accelerator cavity performance and then focus on
Cornell University’s experimental methods for locating defects and how we use them to improve cavity
performance. We adopted the ANL second sound defect location technique three years ago and our
results will be presented.
Alexei Grudiev
CERN
Abstract
No abstract
Tiago Silva
University of Sao Paolo (Brazil)
Abstract
Optical Transition Radiation (OTR) has been used for diagnostic purposes in particle beams for several reasons. For instance, linearity with beam current, polarization, spectrum and time of formation are all characteristics that make OTR an excellent tool to monitor beams in a wide range of energies. It will be presented how OTR plays this important role for a complete beam characterization, as well as some experimental data from an OTR based tool used for the diagnostic of low energy and low current electron beams of the IFUSP Microtron.
Laura Loiacono
University of Texas at Austin
Abstract
Neutrino experiments either specifically study or rely on knowledge about how
neutrinos interact with matter. Absolute neutrino cross sections are determined via
sigma_nu = N_nu/phi_nu , where the numerator is the measured number of neutrino interactions
in a neutrino detector and the denominator is the flux of incident neutrinos. Thus, a
precise understanding of the incident neutrino flux is essential for understanding how
neutrinos interact in matter. Neutrino experiments often utilize the intense flux of
neutrinos that is produced by the decay of pions and kaons in fixed target particle
accelerator facilities. The production of pions and kaons off of the fixed target
contributes significant uncertainty to knowledge of the neutrino flux. Thus, it is desirable
to make in situ measurements of the incident neutrino flux. However, wide band low
energy neutrino beams do not readily lend themselves to in situ flux measurements
unlike narrow band beams.
Past wide band beam experiments have measured the neutrino flux by measuring
the muons produced alongside the neutrinos in pi±-> mu nu_mu and K± -> mu nu_mu decays.
The NuMI wide band neutrino beam, utilized by the MINOS neutrino oscillation and
MINERvA neutrino interaction experiments, has 3 muon monitors which have been
used to measure the muon flux and infer the neutrino flux. We will present a
preliminary measurement of the NuMI neutrino flux obtained from the muon monitoring
system. We also present the muon neutrino charged current inclusive cross section
measured using the the 980 ton MINOS Near Detector and the measured muon neutrino
flux.
Presentation
Valeri Lebedev
FNAL
Abstract
The intrabeam scattering is the major reason of fast luminosity degradation in the Tevatron. It results in that in only about 40% of antiprotons are used to the store end and the rest are discarded. The beam cooling is the only effective remedy to mitigate this problem. Unfortunately neither electron or stochastic cooling can be effective at the Tevatron energy and bunch density. Thus the optical stochastic cooling is the only promising technology capable to cool the Tevatron beam. The paper discuses possible ways of such cooling implementation in Tevatron as well as advances in the optical stochastic cooling theory. The technique looks extremely promising and potentially can double the average Tevatron luminosity without increasing its peak value.
Tim Maxwell
Northern Illinois University
Note Location: Curia II
Abstract
By direct mixing of a broadband laser pulse with picosecond-duration electric fields in an electro-optic crystal, a number of exciting new diagnostic tools achieving unprecedented sub-picosecond time resolution have been devised over recent years. To date these have allowed for ultra-fast (< 50 fs) time of arrival and longitudinal bunch distribution measurements for charged particle beams by direct probing of coherent transition radiation pulses or short-range Coulomb fields. In this talk we elaborate on the design and progress for a single-shot, ultra-fast, minimally interceptive spatio-temporal correlation monitor based on these principles at the A0 photoinjector. When complete, the device has direct applications in providing new feedback diagnostics for future colliders such as the International Linear Collider, as well as light sources such as the free electron laser.
May 18, 2010 (rescheduled from April 20, 2010)
Holger Witte
Oxford
Note Location: Comitium
Abstract
This talk gives an overview of the PAMELA project, which is an initiative to
introduce charged particle therapy using protons and carbon ions to the UK.
PAMELA, which is an acronym for Particle Accelerator for Medical
Applications, employs a novel accelerator concept, a so-called non-scaling,
non-linear FFAG. This colloquium briefly reviews the basic concept and gives
an overview of the status of the PAMELA project. A particular emphasis will
be on the superconducting main accelerator magnets, which feature a novel
helical winding scheme to create the required multipole field.
Juergen Dietrich
Forschungszentrum Juelich, Institut fuer Kernphysik
Abstract
The 2 MeV electron cooling system for COSY-Juelich was proposed to further boost the luminosity even in
presence of strong heating effects of high-density internal targets. The project is funded since mid 2009.
Manufacturing of the cooler components has already begun. The space required for the 2 MeV cooler is
being made available in the COSY ring. The design and construction of the cooler is accomplished in cooperation
with the Budker Institute of Nuclear Physics in Novosibirsk, Russia. The 2 MeV cooler is also well suited in the
start up phase of the High Energy Storage Ring (HESR) at FAIR in Darmstadt. It can be used for beam cooling at
injection energy and is intended to test new features of the high energy electron cooler for HESR. Modifications
to the COSY ring itself and its infrastructure to make space available for the cooler are in progress.
Two new prototypes of the modular high voltage system were developed, one consisting of gas turbines the
other based on inductance-coupled cascade generators. The new 2 MeV electron cooler is described
and tests of components are reported.
Presentation
Tengming Shen
Applied Superconductivity Center
National High Magnetic Field Laboratory
Florida State University
Abstract
Ag-sheathed multifilamentary Bi2Sr2CaCu2Ox (Bi2212) round wire is one
of the leading superconductors that can generate a magnetic field exceeding
the maximum of ~23 T available in present Nb-based superconducting magnet
technology. Despite ongoing research spanning two decades in the area of
Bi2212 conductor and magnet development, the melt processing of powder-in-tube
multifilamentary round wire Bi-2212 to high critical current density Jc remains
complex and empirical, due to the lack of understanding of the complicated
microstructure and its interactions with conductor design and processing.
However, this understanding is critical for both improving conductor Jc and
establishing a reliable wind-and-react Bi2212 magnet fabrication protocol.
Jc of coils, for example, is only ~60% of those of the short sample produced
in a corresponding processing.
This talk will summarize a PhD thesis study that has deconvoluted the complexity
of melt processing using a through-process quench study to reveal how microstructure
develops through processing and to systematically examine the interactions between
microstructure, processing, and Jc. Many fundamental questions regarding 2212
conductor Jc will be discussed. This talk will also examine the fundamental
causes for Jc loss in coils, revealing a Cu loss from melted oxide filaments
as a critical factor. In summary, the study will show strategies by which 2212
Jc can be significantly increased at both conductor and coil level, presenting
the Bi2212 round wire as a strong candidate for the very-high-field magnet
technology.
Presentation
Erik Hemsing
UCLA
Abstract
Free-electron lasers (FELs) use a relativistic electron beam to generate high-brightness, frequency-tunable, coherent photon pulses. Modern FELs operating at x-ray wavelengths have ushered in a new era of scientific research, enabling access to ultra-short and ultra-fast scales. I will describe a new mode of operation for FELs in which higher harmonic resonances are exploited to generate light that carries orbital angular momentum (OAM). OAM light has numerous exotic properties for research; the photons can be used to rotate and twist micro-mechanical systems, for example, or to obtain improved resolution for pump/probe experiments. OAM light is obtained in an FEL by the interaction of the electron beam with a harmonic ponderomotive trapping bucket that has a helical 3D phase geometry, which redistributes either the electrons or the photon phasefronts into a corkscrew. I will discuss this scheme, as well as recent confirmatory numerical simulations. The first proof-of-principle helical microbunching experiment, HELiX at UCLA, due to go online shortly, will also be discussed.
Presentation
Sergei Nagaitsev
Fermilab
Abstract
What prevents us from building super-high intensity accelerators? The answer is case-specific, but it often points to one of the following phenomena: machine resonances, various tune shifts (and spreads), and instabilities. These three phenomena are interdependent in all present machines. In this seminar I will propose a path toward alleviating these phenomena by making accelerators nonlinear. This idea is not new: Orlov (1963) and McMillan (1967) have proposed initial ideas on nonlinear focusing systems for accelerators. However, practical implementations of such ideas proved elusive, until recently.
Rama Yedavalli
Ohio State University
Note Location: Curia II
Abstract
This seminar presents some useful systems level concepts on analyzing and synthesizing control systems from robustness point of view. Robustness is the ability to deliver acceptable performance in the presence of perturbations and as such is closely related to reliability and resilience. The uncertainties in the system can be modeled as real parameter perturbations, unmodeled dynamics, neglected nonlinearities and external disturbances. The system dynamics are modeled both from time domain state space representation as well as frequency domain transfer function representation. Depending on which framework the system dynamics is amenable, robust control techniques suitable for that framework are presented. The proposed robust control philosophy is extended to fault tolerance/failure modes wherein the faulty (or failed) situation is treated as perturbation from the nominal state and the robust control strategy is applied to keep the system stable (and possibly deliver acceptable performance) in the presence of these faults. The proposed robust control methodologies are illustrated with applications in flight control and the possibilities of applying these powerful concepts to control problems in nuclear industry (such as control of superconducting cavities) are explored.
Pantaleo Raimondi
INFN/Frascati
Abstract
The novel collision scheme with "Large Piwinsky Angle and Crab Waist" (LPA & CW) is described. Its implementation on the Dafne Collider and the results are also presented. The SuperB project based on such scheme, aimed at a luminosity of about 10^36cm-2sec-1, will also be presented. General considerations to adapt parts of the scheme to improve the performances of existing colliders will also be shown.
Presentation
Holger Witte
Oxford
Note Location: Comitium
Abstract
This talk gives an overview of the PAMELA project, which is an initiative to introduce charged particle therapy using protons and carbon ions to the UK. PAMELA, which is an acronym for Particle Accelerator for Medical Applications, employs a novel accelerator concept, a so-called non-scaling, non-linear FFAG. This colloquium briefly reviews the basic concept and gives an overview of the status of the PAMELA project. A particular emphasis will be on the superconducting main accelerator magnets, which feature a novel helical winding scheme to create the required multipole field.
Presentation
Chris Polly
FNAL
Abstract
For the last century, measurements of magnetic moments have paved the way to a deeper understanding of physics at the most elementary level. This talk will review the rich historical interplay between experiment and theory in the context of ever-increasing precision, the implication current results have for potential physics discoveries at the Tevatron and LHC, and the prospects for mounting a next generation muon g-2 experiment at Fermilab. In particular, emphasis will be placed on explaining the required modifications to the accelerator complex.
Presentation
Guoxing Xia
Max-Planck Institute, Munich
Abstract
Ion effects are one of the very high priority issues in the damping ring R&D for the Technical Design Phase of the International Linear Collider (ILC). Ions produced from the processes like collisional ionization, tunnel ionization and synchrotron radiation ionization of the residual gas in the vacuum pipe couple the beam motion and cause the two-stream instabilities in the machine. For the ultra-low emittance storage rings with multi-bunch operation, like the ILC damping ring, the single passage instability so-called fast ion instability is prominent and potentially deleterious to the machines performance. In this talk, ion effect issues are reviewed, followed by a detailed simulation study of the fast ion instability in the ILC electron damping ring. Possible cures are proposed as well. In addition, the latest experimental results on the fast ion instability at KEK ATF (Accelerator Test Facility) damping ring are also presented.
Presentation
Srivani Sirisha Motamarri
University of Illinois at Chicago
Abstract
Mechatronics is the synergistic integration of design through mechanical engineering,
electrical engineering, computer science and controls. It defines the current state of
evolutionary change of engineering fields that deals with the design of controlled
electromechanical systems. Advances in embedded computing and availability of
small form factor processors with increased performance and at ever reducing cost
makes possible the use of the computer control in thousands of consumer products,
as well as in various research projects.
This presentation gives an overview of design principles of mechatronics in embedded
motion control systems and discusses some of its applications, in research areas like
motion planning and control, steering control, x-by-wire and precision motion control,
conducted at Mechatronics Laboratory at University of Illinois at Chicago.
Daniel Mazur Abstract
The speaker's background lies in experimental research of surface and interface properties
of condensed matter. His presentation will bring an overview of his past and current projects
that involve techniques and materials relevant to the accelerator materials research.
The presented surface analytic techniques will be the electron tunneling spectroscopy,
scanning tunneling microscopy, the x-ray photoelectron spectroscopy, and a few auxiliary
methods. These are among the principal tools for investigation of materials' surfaces and thin
films, wherein lies their value for future materials development for accelerator cavities and
particle sources. The speaker has been using them regularly over the past 10 years to investigate
a number of materials including superconductors, semiconductors and giant magnetoresistive
crystals. On the surface preparation side the speaker will cover thin film deposition by means
of evaporation, magnetron sputtering and pulsed laser ablation, accompanied by an overview
of deposition masking, photolithography and focused ion beam lithography.
Mohamed Awida Abstract
Slowing the phase velocity of an electromagnetic wave in a low-loss resonant structure to the point that it matches
the particle velocity is the basis for achieving particle acceleration. The properties of twisted waveguide structures
were previously investigated and have shown that slow-wave accelerating fields could be excited within the structure
in contrast to the straight structure where the phase velocities of electromagnetic waves are faster than the speed of light.
Alberto Gola Abstract
In the talk we will discuss the design of a Gamma Camera based on an
array of Silicon Drift Detectors or SDD. The SDD is a relatively new
detector, only recently used for the scintillation light readout. Thanks
to its low electronic noise, combined with a very high quantum efficiency
and unitary excess noise factor, it can be a good candidate for the
scintillation light readout. Due to the absence of charge multiplication,
however, the optimization of the electronic noise is fundamental and care
must be taken in the design of the front end electronics.
The topics of the talk will be: a description of the SDD and its working
principle; its use as the photodetector in a Gamma-ray spectroscopy system
and in a Gamma Camera; a description of the multi-channel analog front-end
for the SDD, designed in integrated electronics, with some details on the
optimal filter theory; the digital processing of the signals coming from
the Gamma Camera. Chris Densham Abstract
The T2K experiment began operating almost 1 year ago. It utilises what is
projected to become the world’s highest pulsed power proton beam at 0.75 MW
to generate an intense neutrino beam. T2K uses the conventional technique of
interacting the 30 GeV proton beam with a graphite target and using a magnetic
horn system to collect pions of one charge and focus them into a decay volume
where the neutrino beam is produced. The target is a two interaction length
(900 mm long) graphite target supported directly within the bore of the first
magnetic horn which generates the required field with a pulsed current of 300 kA.
The talk will describe the design and development of the target system, the
beam windows and the beam dump required to meet the demanding requirements of
the T2K facility. Challenges include radiation damage, elastic stress waves,
design and optimisation of the helium coolant flow, and integration with the
pulsed magnetic horn. Conceptual and detailed engineering studies were required
to develop a target system that could satisfy these requirements and could also
be replaced remotely in the event of failure. Steve Holmes Abstract
Project X is the centerpiece of Fermilab's plan for evolution of the
accelerator complex in the post-collider era. This talk will describe
the constraints in moving Project X through the development phase and
into construction, the strategy that is being pursued to overcoming
those constraints, and the current status of the development program.
A discussion will follow.
Mohammed Al Sharo'a Abstract
Thermal studies of high-pressure RF cavities were performed to analyze the natural
convection in the gas inside the cavity. The natural convection is driven by the deposition
of energy in a circular cross-section along the axis of the cavity. Non-dimensional analysis
was implemented and thermal solutions were obtained over a wide range of geometrical
and thermal variables. In this talk, the thermal results at high values of Rayleigh number
including heat transfer coefficient, flow temperature, and flow velocity will be discussed.
Also, thermal and structural design considerations of RF windows for high-pressure RF
cavities will be proposed.
Abstract The success of Tevatron
Run II is based on advances in the accelerator physics, as well as, on the
excellence and advances in engineering, instrumentation and machine operation.
In this series of lectures we would like to review the main advances in Accelerator
physics which contributed to the luminosity growth and/or improvement of the
Tevatron complex operations. The lectures are aimed for the Run II participants
who would like to deepen their understanding of the accelerator physics. The
level of the presented material corresponds to the advanced course of
accelerator physics but at the same time we would like to present material so
that it could be understandable for less prepared listeners. Valeri Lebedev Abstract The success of Tevatron
Run II is based on advances in the accelerator physics, as well as, on the
excellence and advances in engineering, instrumentation and machine operation.
In this series of lectures we would like to review the main advances in
Accelerator physics which contributed to the luminosity growth and/or
improvement of the Tevatron complex operations. The lectures are aimed for the
Run II participants who would like to deepen their understanding of the
accelerator physics. The level of the presented material corresponds to the
advanced course of accelerator physics but at the same time we would like to
present material so that it could be understandable for less prepared
listeners. Valeri Lebedev Abstract The success of Tevatron
Run II is based on advances in the accelerator physics, as well as, on the
excellence and advances in engineering, instrumentation and machine operation.
In this series of lectures we would like to review the main advances in Accelerator
physics which contributed to the luminosity growth and/or improvement of the
Tevatron complex operations. The lectures are aimed for the Run II participants
who would like to deepen their understanding of the accelerator physics. The
level of the presented material corresponds to the advanced course of
accelerator physics but at the same time we would like to present material so
that it could be understandable for less prepared listeners. Alvin Tollestrup Abstract The physics of the
processes that can lead to breakdown of the cavity and to the destruction of
the cavity Q will be discussed. Seunghwan Shin Abstract Realization of a precise
beam handling is strongly required in future accelerators such as linear
colliders (LC) and X-ray free electron lasers (XFEL). The key component to
realize a precise beam handling is a high resolution beam position monitor. An
RF cavity type beam position monitor (Cavity BPM) is a candidate to measure the
beam position in nano-meter resolution. In this presentation, activities of
cavity BPM R&D at KNU (Kyungpook National university) as well as Fermilab
will be described. Hitoshi Hayano Abstract New Electro-chemical
Polishing facility (EP facility) in STF was commissioned in 2008 by the
collaboration of FNAL cavity. Being connected to this commission, we started
the basic R&D of EP treated niobium surface inside of the cavity. The
purpose of the R&D is to aim high gradient, 35MV/m, the target of ILC. To
get rid of try and error type R&D, we are seeking the method to understand
what is going on the real cavity inside, such as optical inspection of heated
region, application of surface analysis tools to understand what is the
residuals after EP treatment. This is the introduction of our 1-year R&D
effort, still in the beginning stage, such as; XPS, SEM, EDX analysis of EP
treated Nb surface, sulfur removal experiment, optical inspection results, and
tool developments like inspection camera, sponge-wipe mechanics, and local
grinding mechanics. Aida Todri Abstract In this talk, we present
an overview of the design and challenges of power network distributions on
integrated circuits (ICs). We provide a brief perspective on the development of
ICs and introduce the problem of power distribution. As processing technologies
shrink to deep submicron regime, more transistors are packed on the same area
and at the same time leakage currents become non-negligible causing power
consumption and management to become an essential problem. Leakage current
reduction is achieved by shutting power off to the idle circuits on the chip
referred to as power gating. However, implementation of power gating can impose
reliability issues on the power network. We describe the implications and
electromigration mechanism that can occur due to power gating. We additionally,
discuss the signal and power integrity of power networks and their dependencies
to decoupling capacitance efficiency and workload’s frequency for multi-cores
systems. John Consiglio Abstract The Environmental
Protection Agency (EPA) mandates the FTP-75 emissions certification test which
is used to rate the emissions of cars and light trucks sold in the USA. The
test specifies a driving cycle that is representative of real world automobile
usage. The driving cycle loading schedule, however, is derived from simplified
'road load' coefficients and may not match the loadings present in real world
driving situations. A hardware-in-the-loop simulation can be used that will
more accurately predict the loads imparted on the powertrain. Design details of
the hardware-in-the-loop powertrain testing will be presented along with
results from several driving cycles. Sandor Feher Abstract Bringing up the world
largest superconducting magnet system was a great challenge. I summarize this
tremendous effort leading to successfully circulating beams on September 11th
2008. I also pay special attention to interesting features discovered in this process
including the September 19th event. Olivier Napoly Abstract The assembly of the 3
pre-series and 100 series superconducting linac modules is part of the In-Kind
contribution of France to the XFEL project. This operation is planned for the
years 2011-2012 to take place on the Saclay site in a new infrastructure
operated by an industrial company under the responsibility of the CEA/Irfu
department. It will include the assembly of the 103 cavity strings in a new 112
m2 ISO4 clean room and the module assembly in a set of 3 adjacent halls. The
status of this project as well as the ongoing preparation work is described. Laurie Waters Abstract High power accelerators
and spallation targets have a history that goes back to the early 1950's.
Accelerator-driven neutron spallation sources have operated for years, but
broader forays into more industrial applications traditionally handled by
reactors started to receive serious funding in the 1990's with the Accelerator
Production of Tritium (APT) project. Research for this device, which was never
built, led to a series of other ideas, such as Accelerator Transmutation of
Waste (ATW), Advanced Accelerator Applications (AAA), and the Advanced Fuel
Cycle Initiative (AFCI). This talk will review these programs, and summarize
our current impressions of how the concept is viewed by potential funding
agencies today. Hans Weise Abstract
With main emphasis on the XFEL's cold linac a summary of the work done
by the Accelerator Consortium will be given. Final prototyping of components
and the preparation of large call for tenders are the main issues in 2009. The
civil construction was started. Most of the possible in-kind contributions are
identified. Dileep K. Bhogadi Abstract
Currently, cell manipulations for Intra Cyto Plasmatic Cell Injection
(ICSI) are performed manually. These highly precise operations require
high-skilled professional operators. However, the success and survival rate of
the cells is very low due to the great sensitivity of cells. Moreover, while
manipulating, the operator cannot feel any interaction with the cells because
of their negligible mass. Conventional cell manipulation does not have the
ability to provide force feedback to an operator. Therefore all the operations
are based on the visual information provided by the high-precision microscope.
In addition, vibrations of human’s hand can affect the quality of
micromanipuation tasks. Therefore, there exists a need to design a robotic arm
for cell injection process and to incorporate haptic force feedback along with
visual feedback into a cell injection system, with the capability of
representing contact forces in the range of µN-mN. In order to know the contact
forces experiencing by the cell membrane, a good understanding of the
biological cell dynamics throughout the cell injection process is necessary. Nikhil Jethava Abstract
Superconducting Transition Edge Sensors (TES) simple and robust
incoherent continuum detectors, which nevertheless can reach sensitivities
close to the fundamental noise limit. TES offers various advantages over the
traditional semiconducting detector; it is faster, more sensitive, has a higher
dynamic range, allows complete microlithographic fabrication and can be
multiplexed with Superconducting Quantum Interference Devices (SQUIDs). The low
noise SQUID amplifiers operate at bolometer temperatures and have very low
power dissipation. The fabrication of TES with integrated SQUIDs and the
multiplexing electronics will allow the production of bolometer arrays with
several hundred or more pixels. TESs can be used as bolometer (total power
detection) and as micro-calorimeter (energy measurement). I will discuss two of
its applications: 1) detectors for astronomy in millimeter and sub-millimeter
wavelength regime, and 2) micro-calorimeters for nuclear line forensics. I will
present a bolometer system, which is commissioned at an astronomical telescope
site, and a micro-calorimeter system that successfully measured the complicated
plutonium isotopic spectra. James T. Volk Abstract
Understanding slow and fast ground motion is important for the
successful operation and design for present and future colliders. Since 2000
there have been several studies of ground motion at Fermilab. Several different
types of hydro static water levels have been used to study slow ground motion
(less than 1 hertz) seismometers have been used for fast (greater than 1 hertz)
motions. Data have been taken at the surface and at locations 100 meters below
the surface. Data and results of both slow and fast ground motion will be
discussed in particular the effects of natural and cultural sources of motion. Slava Danilov Outline
SNS physics and technology, related to the following issues: Ring
instabilities, space charge, laser stripping. Sequence of developments as SNS
ring intensity increases. Nonlinear accelerator lattices with regular motion
and large tune spread to kill instabilities and mitigate space charge effects. Alexey Burov Abstract
Head-tail modes are described when the space charge tune shift
significantly exceeds the synchrotron tune. Spatial shape of the modes, their
frequencies, coherent growth rates and Landau damping rates are found. Talks in 2008 Robyn Madrak Abstract
We will give updates on the fast chopper and the 325 MHz vector
modulators for HINS. A fast chopper capable of kicking single 2.5 MeV H- bunches spaced at
325 MHz, at rates greater than 50 MHz is needed for the Fermilab High Intensity
Neutrino Source (HINS). Four 1.2 kV fast pulsers, designed and manufactured by
Kentech Instruments Ltd., will drive a 0.5 m long meander made from a copper
plated ceramic composite. Test results showing pulses from the first 1.2 kV
pulser and meander results will be presented. One of the goals of the low energy 60 MeV section of the HINS H- linac is
to demonstrate that a total of ~40 RF cavities can be powered by a single 2.5
MW, 325 MHz klystron. This requires individual vector modulators at the input
of each RF cavity to independently adjust the amplitude and phase of the RF
input signal during the 3.5 ms RF pulse. Two versions of vector modulators have
been developed; a 500 kW device for the radiofrequency quadrupole (RFQ) and a
75 kW modulator for the RF cavities. High power tests showing the vector
modulator phase and amplitude responses will be presented. Stephen Molloy Abstract
The radio-frequency
cavities used to accelerate beams of charged James T. Volk Abstract Since 1995
research and development of permanent magnets has been done at Fermilab. The most
important effort was the building of the Recycler ring for storage of anti
protons. This is a 3.6 km in circumference ring made with 486 magnets all using
strontium ferrite permanent magnets. Up to 450 x 1010 anti protons
are stored in this ring. Basic design parameters and assembly techniques used
for the recycler will be discussed. In addition work done on adjustable
quadrupole magnets will be discussed. These are high field (greater than 100
Tesla per meter gradient) quadrupoles with an adjustable gradient of 20% of
full field. Thomas Hott Abstract The XFEL project
status and the special role XFEL plays for ILC are described. Henryk Piekarz Abstract The arrangement of
a duoplasmatron proton source with its low energy beam transport (LEBT) system
for HINS front-end first tests is described, and proton beam results as well as
some operational issues are presented. Implication of experience gained
with duoplasmatron proton source for a possibility of a Cs-free H-minus source
for the future HINS is discussed. Valeri Lebedev, Dave McGinnis and Sergei Nagaitsev Abstract Paul Derwent Abstract Dariusz Bocian Abstract Jim Norem Abstract Marco Danuso Abstract Alan A. Hahn Abstract Tom Peterson Abstract Manoel Conde Abstract Special time/location: 11 am in Curia II Alexey A. Poklonskiy Abstract Vsevolod (Seva) Kamerdzhiev Abstract Mike Syphers, FNAL Abstract Kirk McDonald Princeton University Abstract Steve Holmes FNAL Abstract Mike Syphers FNAL Abstract Alexander Zlobin FNAL Abstract Yoshihisa Iwashita Kyoto University Abstract Jim Patrick, Brian Hendricks, and Charlie Briegel Fermilab Abstract Emanuela Barzi Fermilab Abstract An ongoing effort
at FNAL and elsewhere focuses on the endeavor of making state-of-the-art
magnets for present and future accelerators. The High Field Magnet and LARP
Programs need high field dipoles and quadrupoles, and Muon Collider R&D
requires very high field solenoids. In the last 10 years, within a Superconductor
R&D program at TD, a large infrastructure, including two short sample test
facilities, a cabling machine to fabricate Rutherford-type cables, and furnaces
for heat treatment, was built upon this need with the mission to serve as an
interface between materials and magnets. This superconductor R&D program
encompasses the study of LTS beyond NbTi, and HTS materials. As a leading
center for conductor technology, for LTS like brittle Nb3Sn and Nb3Al,
our research and scientific studies have focused on the process of cable
development because of the many different phenomena occurring in the round
strand that can deeply modify their performance in magnets. For instance the Nb3Sn
dipole magnet performance can be gravely compromised by flux jump
instabilities, which we found to be inherent to high-Jc Nb3Sn
conductors. For HTS solenoid applications, our program aims at monitoring
state-of-the-art conductors, solving present challenges of tapes and wires, and
developing appropriate cable and coil technologies. These studies, which are
broad in spectrum and scope, will help us develop a most enriching vision for
the future. Raymond Fliller III Fermilab Abstract The A0
Photoinjector is a 16MeV electron linac used for Accelerator R&D. It
consists of a 1.3 GHz copper RF gun and a TESLA type superconducting cavity.
Through its history, multiple beam physics experiments have taken place. Most
recently a transverse to longitudinal emittance exchange beamline has been
installed. This beamline uses a copper 3.9 GHz deflecting mode or crab cavity
between two doglegs to affect the exchange. Data taking for this experiment is
underway. Various mechanisms may dilute this exchange or effect the
measurement. In this talk we will discuss the theory and initial data taking
for the emittance exchange, and the physics that can dilute it, such as
Coherent Synchrotron Radiation. We will also discuss other R&D activities
that have applications to other machines which may be built at Fermilab such as
the ILCTA-NML. Valeri Lebedev Fermilab Abstract Recent stacking
rate records are the result of many improvements in Antiproton Source. Details of the
work carried out during last 1.5 year and
the accelerator physics behind them will be discussed. Giulio Stancari INFN Ferrara Abstract Francium is one of
the best candidates for measurements of atomic parity violation and for the
search of permanent electric dipole moments. These fundamental measurements
rely on precision studies in atomic spectroscopy and on the development of
magneto-optical traps. A radioactive francium beam facility has been
commissioned at INFN's national laboratories in Legnaro, Italy. The physics of
francium production and trapping will be discussed, together with some of the
technical challenges involved and a summary of recent results. Several options
are being considered for future upgrades of this unique facility, including the
new concept of a recirculating-beam ion source, which combines ionization
cooling of a stored primary beam with a thin internal production target. Riccardo de Maria CERN Abstract The seminar is
focused on beam optics design studies on interaction region layouts for a LHC
luminosity upgrade. Two layouts options "dipole first" and
"quadrupole first" are analyzed and compared. Ralph Assman CERN Abstract The Large Hadron
Collider at CERN will store and collide proton and ion beams with unprecedented
intensities and destructive potential. Small fractions of the beam can be lost
during operation. These losses require highly efficient and robust collimation
such that the accelerator is protected against quenches and damage. The
loss-induced challenges for the LHC are reviewed and the collimation system is
described. Special focus is put on future research requirements for collimation
upgrades and on opportunities for inter-laboratory collaborations. S.Yu. Kazakov KEK Abstract The general
principles, design solutions and performance of the high-power RF sources the
author worked on are considered for both “warm” and SC versions of a linear
collider. The problems of high–power RF windows for accelerator applications,
as well as the several types of the new windows the author invented, are discussed.
The power multiplication schemes and examples of the some exotic high RF power
components the author developed for these schemes are described, namely mode
launchers, mode converters, power dividers, phase shifters, etc. The design and
test results of a new, inexpensive and simple sectioned high-power input
coupler for the SC collider option, developed by the author for ILC SC
cavities, are presented. Finally, the results of the work on an ultra-fast
electrically-controlled L-band ferroelectric tuner, which allows fast coupling
and phase control of the SC acceleration cavities, are presented. November 14, 2007 (special seminar!) Chris Tschalaer, Bill Franklin, Aleem Siddiqui and Fuhua Wang MIT/Bates Abstract The talk will be split into four parts: Presentation Angelo Dragone Brookhaven National Laboratory Abstract During the last
ten years, the development of microelectronics for radiation detector
applications has faced a big impulse. Starting from pure analog ASICs
integrating a few channels designed according to the classical front end
schemes, more and more functionalities have been added. Realtime processing of
the signals, at first in the analog domain and lately in the digital one,
arbitration and multiplexing schemes have been introduced to reduce the number
of interconnections and the amount of information to transfer to the data
acquisition systems. During this talk a few examples of architectures developed
at Brookhaven National Lab during the last four years will be presented with
the aim to give an overview of the groups' and personal expertise. Mike Tartaglia Fermilab Abstract The International
Linear Collider reference design requires over 13000 magnets, of approximately
135 styles, which must operate with very high reliability. The Fermilab Main
Injector represents a modern machine with many conventional magnet styles, each
of significant quantity, that has now accumulated many hundreds of magnet-years
of operation. We review here the performance of the magnets built for this
machine, assess their reliability and categorize the failure modes, and discuss
implications for reliability of similar magnet styles expected to be used at
the ILC. Linda Klamp Spentzouris Illinois Institute of Technology Abstract IIT is one of
several universities in the Chicago area with faculty and graduate student
research in the area of accelerator physics. The present status of graduate
student projects on the topics of metamaterial-loaded waveguides and Booster
space charge studies will be reviewed. The metamaterial-loaded waveguide work
was motivated by the possibility of customizing the dispersion function of the
loaded waveguide, with the potential of suppressing higher-order modes.
Calculational work and preliminary experimental data will be discussed. A
Booster space charge coupling study will be presented, along with a discussion
of status and future plans. Presentation October 02, 2007 Sergey Strokov University of Hiroshima Abstract The crystals are
good candidates to use them in a beam extraction device at J-PARC and in a beam
collimation device at ILC. The results of the experiments on deflection of
electrons and protons performed in Japan will be presented. The prospect of the
future channeling experiments in Japan will be discussed as well. Presentation September 18, 2007 Abstract Breakdown is a
limiting factor in rf devices from cavities for particle accelerators to
waveguides for tokomak heating and rf delivery. Modeling breakdown is challenging
because of the need to handle the generation and behavior of impurities.
Processes such as sputtering, charge exchange, multiple ionization, and
radiation are all important, but are not typically handled in traditional
breakdown codes. I will discuss how we are addressing the challenges
above in two particle-in-cell codes: OOPIC Pro and VORPAL. Presentation Studies of Charged Particle Beam Dynamics on
the Paul Trap Simulator Experiment (PTSX) Moses Chung Plasma Physics Laboratory, Princeton
University Abstract At the high beam
intensities envisioned in present- and next-generation accelerators, a
fundamental understanding of the influence of collective processes and
self-field effects on beam transport and stability properties must be
developed. To address these issues experimentally, the Paul Trap Simulator
Experiments (PTSX) device was proposed and constructed at the Princeton Plasma
Physics Laboratory (PPPL). The PTSX device is a cylindrical Paul trap that
simulates a long, thin charged-particle bunch coasting through a
kilometers-long alternating-gradient (AG) magnetic transport system by putting
the physicist in the beam’s frame-of-reference. The transverse dynamics of
particles in both systems are described by similar equations, including all
nonlinear space-charge effects. In this talk, descriptions of the PTSX device
and diagnostics are given, related theoretical backgrounds are summarized, and
experimental results on beam mismatch, transverse beam compression, random noise
effects, and collective modes are presented. Experimental results are also
compared with WARP particle-in-cell (PIC) simulations. Presentation August 30, 2007 Zachary Conway ANL Abstract Multi-spoke-loaded
superconducting niobium accelerator cavities are being developed for heavy-ion
accelerators with application to both cw and pulsed ion linacs necessary for
several proposed accelerator facilities. Multi-spoke cavities have been developed
to accelerate ions from protons through uranium over the velocity range
spanning 0.35 < beta < 0.75. Recent results of cold tests, focusing
on the mechanical properties and the dramatically-improved RF performance will
be presented. Presentation Lance Cooley FNAL Abstract Superconducting
materials for RF linear accelerators have attracted renewed attention, thanks in
large part to present and former Fermilab personnel who have organized and
hosted a series of workshops in recent years. I will review the latest of
these, held this past May, which marks an important expansion from a regional
meeting into a truly national meeting with >70 attendees. The workshop
focused on topics such as theoretical limits to superconducting RF,
understanding the basic materials science of niobium, surface characterization
techniques, other superconducting materials, alternative processing strategies,
and niobium processing and cavity fabrication. I will discuss highlights from
each of these areas, and describe their potential impact on the ILC. In
addition, since niobium is an enabling technology for very high gradient
accelerators, I will explore implications of workshop presentations for SRF
science in general, including the possibility for generating gradients beyond
the limits of niobium. An important by-product of the workshop expansion has
been recognition of basic work by funding agencies, and I will discuss briefly
my opinion about future materials research. Fanglei Lin Indiana University
Abstract Two partial helical dipole snakes have been employed
successfully to overcome all imperfection and intrinsic spin resonances in the
AGS provided that the vertical betatron tunes were maintained in the spin tune
gap near the integer 9. However, the measured maximum 65% polarization at the
AGS extraction energy shows still about 20% polarization loss comparing with
the injected 82%. Except for the horizontal intrinsic resonances introduced by
the two partial snakes, there were also polarization drop due to the residual
vertical intrinsic resonances, partial snake resonances and orbit distortion
where the vertical betatron tune beyonds 8.99. This talk presents the
investigation of polarization of proton beam in the AGS, including the
experimental results and simulations. Possible cures of the remaining beam
polarization are also discussed. Presentation Resonant multi-turn extraction project: principle
and experiments at the CERN Proton Synchrotron Massimo Giovannozzi CERN Abstract Recently a novel
approach to perform multi-turn extraction was proposed based on beam splitting
in the transverse phase space by means of trapping inside stable islands. In
addition to numerical simulations, aimed at assessing the feasibility of the
proposed technique, an experimental campaign was launched since the year 2002
at the CERN Proton Synchrotron. During the year 2004 run, a high-intensity
single-bunch beam was successfully split and the generated beamlets separated
without any measurable losses. The underlying principle will be presented and
discussed in details as well as generalizations of the method to multi-turn
injection and the latest experimental results. Presentation E. Métral (work
with G. Rumolo, B. Salvant and R. Tomás) CERN, Abstract Since 2003,
high-intensity single-bunch proton beams with low longitudinal emittance have
been affected by heavy losses after less than one synchrotron period in the
CERN SPS. Measurements of the turn-by-turn evolution of the instability have
been compared with HEADTAIL simulations, exhibiting a remarkly good agreement.
In both cases, a travelling-wave pattern propagating along the bunch was
clearly identified, which was believed to be the signature of a Transverse Mode
Coupling Instability. Recently, using SUSSIX to analyze tracking data from
HEADTAIL via frequency analysis, previous predictions from MOSES, which
computes the coherent bunched-beam modes, have been confirmed. In particular,
using the SPS beam parameters, a coupling between the azimuthal modes -2 and -3
is taking place. This regime of TMCI is more intricate than the one observed in
the past with leptons as the proton bunches are much longer. The next step will
be to perform measurements in the SPS to verify this prediction. Presentation June 21, 2007 Longitudinal Emittance Control in the
CERN PS Heiko Damerau CERN Abstract Thorough control
of the longitudinal emittance is essential for the Presentation Status of the LHC
Inner Triplets Jim Kerby Fermilab Abstract The status of the
LHC inner triplets will be described. Parametric studies
for a phase-one LHC upgrade based on Nb-Ti Ezio Todesco CERN Abstract Accelerator
Division Roger Dixon Fermilab Abstract Presentation Craig Drennan Fermilab Abstract To better control
the beam position, tune, and chromaticity in the Fermilab Booster synchrotron,
a new package of six corrector elements has been designed, incorporating both
normal and skew orientations of dipole, quadrupole, and sextupole
magnets. The devices are under construction and will be installed in 48
locations in the Booster accelerator. Each of these 288 corrector magnets
will be individually powered. Each of the magnets will be individually
controlled using operator programmed current ramps designed specifically for
the each type of Booster acceleration cycle. This presentation will
provide an overview of the corrector magnet installation in the accelerator
enclosure, power and sensor interconnections, specifications for the
switch-mode power supplies, rack and equipment layouts, controls and interlock
electronics, and the features of the operator interface for programming the
current ramps and adjusting the timing of the system triggers. Presentation Recent machine and beam
line optics developments in the Antiproton Source Vladimir Nagaslaev
(Fermilab) Abstract Antiproton
production at Fermilab is a multistage process that uses 2 cooling rings and
more than a kilometer of beam lines. During recent years numerous efforts and developments
were put forward in order to substantially increase the production rate. One of important
parts of these efforts was the optics developments, such as improving machines
acceptance, optimizing beam parameters for the stochastic cooling and optical
matching of the beam lines. The current status of this work and plans for the
near future are presented. Presentation May 15, 2007 Experimental
Optimization of TTF2 RF Photoinjector and
Bunch Compressors Yujong Kim, Free Electron Laser Laboratory, Duke University Abstract To develop various technologies for a future linear
collider and the European X-ray Free Electron Laser, conversion of DESY TESLA
Test Facility (TTF) into its phase 2 (TTF2 / FLASH) was started
in 2002. To get an FEL lasing and a saturation of FEL power within a 30 m long
undulator, highly dense and cold beams with a high peak current, a low energy
spread, and a low emittance should be sent to the undulator. In 2004,
commissioning of a new L-band RF gun, a new superconducting booster linac
(ACC1), and two new bunch compressors were started to supply suchlike beams.
During this talk, speaker will shortly introduce TTF2, RF photoinjector, and
bunch compressors. Then, speaker will talk about various commissioning experiences
of TTF2 RF photoinjector and the first experimental demonstration of a strong
emittance damping along the booster linac to generate a ultra-low normalized
transverse emittance of about 1 mm.mrad for 1 nC and 4.4 ps rms long electron
beams. Finally, speaker will talk about experimental optimization of TTF2 bunch
compressors to generate femtosecond long electron beams. Presentation Accelerator
Driven Nuclear Energy - The Thorium Option Rajendran Raja Abstract A Fast
Chopper for the HINS Robyn Madrak Abstract Presentation LHC
Commissioning and Status Lucio Rossi Abstract Presentation Test
automation, quality control and simulation of superconductors Vito Lombardo Abstract To achieve a full
understanding of accelerator magnets behavior, it is important to test and
characterize superconducting strands and Rutherford-type cables used in the
coils. All existing hadronic accelerators employ a magnet technology based on
NbTi strands. However, NbTi has reached its limit, providing a nominal field of
8.4 T in superfluid Helium for the Large Hadron Collider (LHC). To increase the
operating field and push the energy envelope, new superconductors with better
properties will be needed. Fermilab is currently involved in developing the
next generation of high field magnets with nominal fields of 10-15 T using
Nb3Sn, Nb3Al and High Temperature Superconductors. Solutions to automate data
acquisition and test procedures on two cryogenic short sample test stations of
TD Superconductor R&D lab are presented for critical current measurements
as well as RRR and low field instability. Temperature control, data fitting,
analysis and storing procedures as well as ha rdware and software quench
protection systems have been embedded to keep the human intervention as low as
possible. Applications and results are shown. The cable fabrication procedure
used at Fermilab is then described, together with a laser based solution for
online measurement of the geometry of the cable itself. Finally, results of
simulations of electromagnetic and thermal processes in Rutherford- type cables
are presented. Presentation Status/Plans
for Technical Division Marc Ross Abstract The talk presents
the current status and plans for the Technical Division. Elastic
Splashes Torben P. Grumstrup Abstract When a falling drop
impacts a thin liquid surface, the resultant splash involves the competition of
inertia, viscosity, and surface tension; in certain limits the familiar
crown-shaped splash results. In the case of viscoelastic liquids (either
polymer or micellar) there is typically much less of a splash due to the high
extensional viscosity of these fluids. Here, a novel cross between these two
cases is presented: the splash of two Newtonian liquids which only become
viscoelastic during the splash. A high-speed digital video camera is used to
capture the splash caused by a drop of sodium salicylate solution falling onto
a film of cetyltrimethylammonium bromide solution. When the two combine,
microscopic tubes called worm-like micelles form, causing the liquid mixture to
exhibit viscoelastic properties. The elasticity of the liquid results in
formation of stable liquid filaments and the "beads-on-a-string"
phenomenon -- behavior which would not occur in a Newtonian liquid such as
water. Presentation Electron
Cloud measurements in the High-Current Experiment Michel Kireeff Covo University of California at Berkeley, Department of Nuclear
Engineering, 4155 Etcheverry Hall, MC 1730, Berkeley, California 94720, USA Abstract The High Current
Experiment (HCX) at LBNL is a driver scale single beam injector that provides a
1 MeV K+ ion beam current of 0.18 A for 5 µs. It transports
high-current beams with large fill factor (ratio of the maximum beam envelope
radius to the beam pipe radius) and low emittance growth that are required to
keep the cost of the power plant competitive and to satisfy the target
requirements of focusing ion beams to high-power density. Beam interaction with
the background gas and walls desorbs electrons that can multiply and
accumulate, creating an electron cloud. This ubiquitous effect grows at higher
fill factors and degrades the quality of the beam. A review of the
instrumentation tools used to measure electron production, accumulation and its
properties will be presented and discussed. Presentation Measurements
and Data Analysis in LHC Superconducting Magnets CERN Abstract The assessment of
the training quench performance and of the field quality of the LHC magnets
belong to the acceptance criteria to qualify the dipoles and the quadrupoles for
the LHC machine. One source of the quench at 1.9 K is the release of the
transient energy induced by mechanical perturbations (spikes) during the magnet
powering. These disturbances are localized and studied through voltage
signals recorded across the magnet coils and through signals coming from a
quench antenna. A new measurement station implemented to record the spike
events with a high sample rate and a new analysis method based on the
Continuous Wavelet Transform are described. Results of measurements carried out
on LHC dipoles are presented as well as the statistical treatment of the data
in order to understand the impact of the spikes to the so called training
phenomenon. Un-corrected static
and dynamic magnetic field errors can also degrade the machine performance. The
ramp rate induced field errors and the AC energy loss were studied on the main
LHC quadrupoles and dipoles. The experimental set–up and the results are
compared to the values specified from the beam tolerances. Presentation Metamaterial-loaded Waveguides for Accelerator Applications Sergey Antipov ANL Abstract Material
properties are central to the field of accelerator physics. One area of
advanced accelerator research is to investigate novel materials and structures
and their potential use in extending capabilities of accelerator
components. Within the past decade a new type of artificially constructed
material (metamaterial, MTM) having the unique property of simultaneously
negative permittivity and permeability has been realized, and is under intense
investigation, primarily by the optical physics and microwave engineering
communities. Metamaterials can be customized to have the permittivity and
permeability desired for a particular application. Some unusual effects can be
demonstrated in metamaterials, like negative refraction and backward Cherenkov
radiation. An
investigation of metamaterials in the context of accelerator physics is being
carried out by IIT and the Argonne Wakefield Accelerator Facility. Artificial
materials have potential applications in active and passive devices at
millimeter waves and at much higher frequencies. Waveguides loaded with
metamaterials are of interest because the metamaterials can change the
dispersion relation of the waveguide significantly. For example, slow backward
waves can be produced in a MTM-loaded waveguide without having corrugations.
The dispersion relation of a MTM-loaded waveguide has several interesting
frequency bands. Presentation D.
Marreiro Illinois
Institute of Technology Abstract Presentation or
Muon Collider Derun Li Center for Beam Physics Abstract A Beam Condition Monitoring System for the CDF Experiment R.
Wallny (UCLA) Abstract Six Dimensional Phase Space Cooling Simulation for a Muon Collider K.
Yonehara (Fermilab) Abstract Presentation Observations of Proton Reflection on Bent W.Scandale
(CERN) for
the H8-RD22 collaboration Abstract We report observations, performed by the H8-RD22
Collaboration, of the so-called volume reflection effect with 400 GeV/c protons
interacting with bent Silicon crystals in the H8 beam line at the CERN SPS. The
volume reflection is closely related with particle channeling. This phenomenon
occurs at the tangency point of a particle trajectory with the bent crystalline
planes and consists in the reversal of the transverse component of the particle
momentum. The measurements were collected with a high spatial resolution
detector mainly based on Silicon strips. The proton beam was deviated in the
direction opposite to that of channeling by ~12murad, which is ~1.3 times the
critical angle, with an efficiency larger than 97% in a range of the
proton-to-crystal incident angle as large as the bending angle of
crystallographic planes. This evidence opens new perspectives for manipulation of
high-energy beams, e.g., for collimation and extraction in the new-generation
of hadron colliders or as a method for high-energy experiments in the region
near to the circulating beam. Presentation Note Location & Time Changed ** **Location 1-West** Time 2pm J-PARC Status and Channeling Experiments in Shin'ya
Sawada (KEK) Abstract Superconducting
RF cavities and materials issues Claire
Antoine (Saclay/Fermilab) Abstract The employ of
Superconducting Radiofrequency cavities is main technology asset for the next
generation international collider ILC. SRF technology is also widely used or
foreseen in other particles accelerators, such as light sources (synchrotron,
SASE-FEL, ERL) or high power hadrons beams for neutron sources and nuclear
physics (SNS, ATLAS, RIA). Any of these applications can be very demanding in
terms of specific performance, i.e. high accelerating gradient and/or low
losses, but some of these specifications, achieved on lab scale, are not yet
met on an industrial scale. Basic R&D on the material is a way to better understand
the origin of degradation or dispersion of performances, and how to overcome
it. As a first step we
will describe shortly the main particularities of RF superconductivity, then we
will retrace the last 15 years of SRF R&D, and we will try to show how a
better understanding of the physics of the RF superconductivity helped to
overcome technical limitations. In the third part we will try to summarize the
latest issues in cavities performances, well as the main research directions
that need to be pursued. ALTERNATIVE RF SOLUTIONS FOR HIGH GRADIENT INVESTIGATIONS Vyacheslav
P. Yakovlev Omega-P,
Inc., Abstract Several
RF technical alternative solutions are discussed for elements of future
high-gradient linear accelerators, including RF sources and RF pulse
manipulation systems. The current state of development is summarized for
high-power, high efficiency magnicons at X-band, Ka-band, and L-band as RF
sources for high-gradient R&D and linear collider applications. A new
concept of an active RF pulse compressor based on use of newly-developed,
ultra-fast, electrically-controlled ferroelectric elements is described.
Finally, designs of fast, low-loss, external ferroelectric tuners are described
to provide rapid, precise phase and amplitude control of SC RF cavities of ILC. The
Second Low Emittance Muon Collider Workshop Rolland Johnson Muons, Inc Abstract We report on the
considerable progress that has been made since the first Low Emittance Muon
Collider workshop, which explored the consequences of extreme beam cooling in
order to get high luminosity with fewer muons. Recent measurements
on high-gradient hydrogen-pressurized RF cavities and designs of high-field
high-temperature superconducting magnets show great promise for effective muon
cooling. A momentum-dependent version of the original helical cooling
channel has been developed into a 6-dimensional demonstration
experiment with an elegant magnet configuration that includes emittance
matching. Increased workshop involvement by the high energy
physics community has generated enthusiasm to reexamine the theoretical
goals and experimental possibilities for this new kind of energy-frontier muon
collider, which can use ILC accelerating structures. February 13,
2007 Muon cooling and future muon facilities Daniel M. Kaplan Illinois Institute of Technology Abstract Muon colliders and neutrino factories are attractive
options for future facilities aimed at
achieving the highest lepton-antilepton collision energies and precision measurements of parameters of the
neutrino mixing matrix. The performance and
cost of these depend sensitively on how well
a beam of muons can be cooled. Recent progress in muon cooling design studies and prototype tests nourishes
the hope that such facilities can be built
during the next decade. The status of the
key technologies and their various demonstration experiments will be summarized. Performance of
the LHC Injectors and Intensity limitations Gianluigi Arduini CERN Note Location & Time Changed ** **Location 1-West** Time 10am February 08, 2007 Overview of the
High Intensity Neutrino Source Jean-Paul Carneiro (FNAL) Abstract FNAL is developing the
design and technology of an 8 GeV H-minus superconducting linac with a primary
mission of increasing the intensity of the Main Injector for the neutrino
program. Considerable effort has gone into the development, cross-checking, and
utilization of simulation codes. Start-to-end simulations, from the RFQ to the
Main Injector stripping foil, using the codes TRACK (ANL), ASTRA (DESY) and
ELEGANT (ANL) will be presented to provide a detailed description of this
accelerator. The scope and status of the linac front-end currently being built
at the February 01, 2007 Beam control and monitoring with FPGA-based
electronics: status and Perspectives Nathan Eddy FNAL Abstract Modern FPGAs support designs
using roughly 10^6 logic gates, pipeline speeds exceeding 200 MHz, internal
SRAM, dedicated multipliers for signal processing, clock generation using
phase-locked loops, and a variety of single-ended and differential I/O
standards, including fast serial links. When interfaced with high-speed
ADCs, DACs, and other components commonly found in telecom applications, FPGAs
facilitate a wide range of beam control and monitoring applications.
Examples include beam-position measurement, low-level RF control, instability
damping, and manipulation of accelerator timing signals. Once signals of
interest are in digital form, an instrument's FPGA logic and memory provide a
natural means to capture data for remote diagnosis--both of beam behavior and
of the instrument itself. Finally, FPGA-based solutions provide a
flexible, reconfigurable, and reusable toolkit for instrumentation: existing
modules are often adapted to implement new applications, and useful code
fragments can be quickly copied from design to design. The Future of
Accelerator R&D at Fermilab Steve Holmes (FNAL) Abstract January 23, 2007 Electron-Proton
Dynamics for Long Proton Bunches in High Intensity Proton Rings Yoichi Sato Abstract Electron clouds in intense
space charge dominated proton beams may cause instabilities and emittance
growth. Colleagues at the Oak Ridge National Laboratory (ORNL) and I have
developed an electron cloud module and implemented it into the ORBIT Code for beam
dynamics in high intensity rings. This electron cloud
module includes full 3D descriptions of the proton beam bunch and the electron
cloud, including their space charge interactions and their motion in external
electric and magnetic fields. The two main sources of
electrons are primary electrons caused by lost protons hitting the vacuum
chamber walls and secondary emitted electrons caused by electrons hitting the
wall. For the latter we adopt a set of models based on those of M. Pivi and M.
Furman. This seminar presents
the development of the new electron cloud module, including benchmarks
demonstrating its capability to examine the effects of the electron cloud on
the proton beam and simulation studies of electron cloud dynamics. These
studies include the sensitivity of the electron cloud properties to different
proton beam profiles and reproduction of experimental results from the proton
storage ring at Los Alamos National Laboratory. A possible idea to reduce the
electron cloud effect in the vacuum chamber is also proposed. It will be
applicable to many existing devices easily. Presentation Longitudinal
electron bunch diagnostics using coherent transition radiation Daniel Mihalcea FNAL Abstract The longitudinal charge distribution
of electron bunches in the Fermilab A0 photo-injector was determined using the
coherent transition radiation produced by electrons passing through a thin
metallic foil. The auto-correlation of the transition radiation signal was
measured with a Michelson-type interferometer. The response function of the
interferometer was determined from measured and simulated power spectra for low
electron bunch charge and maximum longitudinal compression. Kramers-Kronig
technique was used to determine longitudinal charge distribution. Measurements
were performed for electron bunch lengths in the range from 0.3 to 2 ps (rms). January 04, 2007 Essential features
of LARP strands and prospects for still better high-field Lance Cooley Condensed Matter Physics and
Materials Science Department Brookhaven National
Laboratory Abstract Since the late 1990s, work
spearheaded by advanced technology development programs in the DOE Office of
High Energy Physics has led to the doubling of the critical current density of
Nb3Sn superconducting wire at 12 T, 4.2 K. As a result of this work,
suppliers of reproducible, reliable, high-performance Nb3Sn strand for advanced
high-field magnet development now exist. The strand design for the LHC
Accelerator Research Program (LARP) typifies many of the critical advances, and
I will describe the general features that enable its success and present an
overview of the materials science beneath them. I will argue that ample
room exists for continued innovation, improved margins, and cost
reduction. Other drivers, such as a very high field solenoid for muon
cooling or the development of superconducting RF cavities beyond pure Nb, may
pull the attention of the materials community away from further developing
Nb3Sn strand, and I will briefly describe emerging areas in high-field
superconducting materials. Talks
in 2006 Main Injector
Digital Dampers Dr. Phil Adamson ( Abstract The Main Injector digital
damper system has been essential in allowing the MI to reach beam intensities of
over 3E13 protons. The present system is described, and upgrade plans for the
proton plan and SNuMI eras are detailed. Presentation Results in the 3-D simulation for Booster Xi Yang FNAL Abstract In
order to have a better understanding of the FermiLab Booster beam loss at
the injection, emittance growth at the transition crossing,
and momentum spread reduction at the extraction, we need a 3-D
model which includes the longitudinal and transverse space charge effect
and the longitudinal impedance effect. After we’ve
successfully bench marked the longitudinal motion model against the experiment
(see the accelerator physics and technology seminar at 09/02/06), it has been
added to the particle tracking code STRUCT. Also, a simplified transverse
space charge model has been added to STRUCT. Based upon our
simulation, the momentum reduction at the extraction is optimized operationally
to reduce the beam loss during Slip Stacking in the Main
Injector. We obtained a good agreement between experiment and simulation
at injection and extraction. We’re ready to include the longitudinal
impedance module and nonlinear chromatic effect at the transition in STRUCT. The CDF Roman-Pot Detectors Mary Convery FNAL Abstract Roman-pot detectors located
in the Tevatron tunnel in the downstream antiproton direction were used in Run
IIa as part of the CDF diffractive physics program. The concept of a
Roman-pot detector will be discussed, as well as the specific design of the CDF
pots. The reconstruction of the kinematics of diffractively-scattered
antiprotons using tracks in the RP detectors and transporting back through the
Tevatron magnets between the pots and the interaction point will be
described. Issues related to beam backgrounds and the operation of
readout electronics in a high-radiation environment will be touched upon, and a
brief comparison to the D0 forward detectors will be given. Diffractive
physics results using the Roman pots will be presented. Presentation Beam control and monitoring with FPGA-based
electronics: status and Perspectives Nathan Eddy FNAL Abstract Modern FPGAs support designs
using roughly 10^6 logic gates, pipeline speeds exceeding 200 MHz, internal
SRAM, dedicated multipliers for signal processing, clock generation using
phase-locked loops, and a variety of single-ended and differential I/O
standards, including fast serial links. When interfaced with high-speed
ADCs, DACs, and other components commonly found in telecom applications, FPGAs
facilitate a wide range of beam control and monitoring applications.
Examples include beam-position measurement, low-level RF control, instability
damping, and manipulation of accelerator timing signals. Once signals of
interest are in digital form, an instrument's FPGA logic and memory provide a
natural means to capture data for remote diagnosis--both of beam behavior and
of the instrument itself. Finally, FPGA-based solutions provide a
flexible, reconfigurable, and reusable toolkit for instrumentation: existing
modules are often adapted to implement new applications, and useful code
fragments can be quickly copied from design to design. Presentation Accelerator Vacuum 101 Made Easy Terry Anderson FNAL Abstract This
talk presents a condensed, simplified, and practical discussion of the
principles, procedures, and operating parameters of particle accelerator vacuum
systems as practiced at Fermilab. It is intended to provide a basis for
designers, builders, and operators of accelerator systems to communicate with
each other about the needs and impact of the vacuum system. Rigorous
analytical development of the equations and concepts are not given. It is
assumed that the reader has some limited understanding of the subject.
References for further study are given in the appendix. Presentation November 09, 2006 Electromagnetic and Mechanical Properties
of Superconducting Spoke-Loaded Cavities Zachary Conway ANL/UIUC Abstract External
forces excite mechanical vibrations in superconducting cavities and lead to
cavity RF frequency variations. The RF control system must be able to
accommodate these frequency variations in order to limit RF field phase and
amplitude errors. Traditionally this was done by increasing the power
output of the RF power source. Another option is to operate fast
mechanical tuners to counterbalance the cavity frequency variation. This
presentation reports on measurements of the external forces, which couple to
the cavity RF field, and on the fast mechanical tuning systems used to
counterbalance their effects for spoke-loaded intermediate-b superconducting cavities being developed
for both cw and pulsed operation. These cavities are of broad interest
for new high-energy ion and proton linacs. Presentation November 02, 2006 The MI Wide Aperture Quadrupole (WQB)
Project FNAL Abstract In
the design stage of the Main Injector it was recognized that the old Main Ring
quadrupoles would pose an aperture limit at the injection and extraction
points, especially at the locations where they are positioned between two
Lambertson magnets. With the increasing beam intensities required to
support neutrino production in the NuMI beam line, the problem became more
pressing. This deficiency has now been corrected by replacing those
limiting magnets with newly designed and constructed quadrupoles that have the
same length and integrated gradient as the old magnets, run on the same bus,
but have a pole tip diameter greater by 32%. We will describe the magnet
design, construction, measurement, installation, and operation, as well as
demonstrating success in matching the Main Injector optics and increasing the
aperture. October 24, 2006 H- laser stripping experiments
at SNS V. Danilov ORNL, Abstract Thin
carbon foils are used as strippers for charge exchange injection into high
intensity proton rings. However, the stripping foils become radioactive and
produce uncontrolled beam loss, which is one of the main factors limiting beam
power in high intensity proton rings. Recently, SNS accelerator team presented
a scheme for laser stripping of an H- beam for the SNS ring. First,
H- atoms are converted to H0 by a magnetic field, then H0
atoms are excited from the ground state to the upper levels by a laser, and the
excited states are converted to protons by a magnetic field. This paper
presents the results of the SNS laser stripping proof-of-principle experiment.
The experimental setup is described, and possible explanations of the data are
discussed. Presentation October 19, 2006 Electron cooling
at the Recycler: Update and Cooling force characterization Lionel Prost FNAL Abstract Electron cooling of 8 GeV
antiprotons at Fermilab’s Recycler storage ring is now routinely used in the
collider operation. It requires a 0.1-0.5 A, 4.3 MeV dc electron beam and is
designed to increase the longitudinal phase-space density of the circulating
antiproton beam. I will briefly describes the characteristics of the electron
beam that were achieved to successfully cool antiprotons. Then, results from
various cooling force measurements along with comparison to a non-magnetized
model are presented. Finally, operational aspects of the implementation of
electron cooling at the Recycler are discussed, such as adjustments to the
cooling rate and the influence of the electron beam on the antiproton beam
lifetime. Presentation Analysis of
beam-beam diffusion effects in RHIC and the LHC Vahid Ranjbar FNAL Abstract The Diffusion analysis
approach to lifetime calculations allow a significant reduction in the time and
computing power usually necessary to perform direct lifetime calculations. We
report on results of diffusion analysis for RHIC and the LHC and consider the
range of validity for this approach. NEW MATERIALS AND
DESIGNS FOR HIGH-POWER, FAST PHASE SHIFTERS Robin Madrak FNAL Abstract In the 100 MeV H- Linac to
be constructed at Fermilab, the use of fast ferrite high power phase shifters
will allow all of the accelerating RF cavities to be driven by a single 2.5 MW,
325 MHz klystron. This results in substantial cost savings. The shifters are
coaxial with aluminum doped Yttrium Iron Garnet (YIG) ferrite. In combination
with branch line couplers, they will provide independent phase and amplitude
control for each cavity. This is achieved by adjusting the solenoidal magnetic
field applied to the ferrite. We report on our results in both low power
(timing) and high power tests, for both 3?? and 1- 5/8?? OD phase shifters. The
low power measurements demonstrate that the rate of phase shift is well within
the spec of 1 degree/µs. The high power tests were performed at the Advanced
Photon Source at Argonne National Lab. We measured phase shifts and the failure
point (applied power) for tuners in various configurations. In addition, we
performed phase and amplitude measurements for a setup consisting of a
1-5/8??OD phase shifter along with a prototype branch line coupler. Beam Commissioning
Software Developed by Fermilab for the LHC David McGinnis FNAL Abstract Fermilab wants to be involved in the
commissioning and operations of the LHC. For example, we are making a
substantial investment in remote operations. It is difficult for outside
visitors from other labs to make important contributions once beam commissioning
has started. These difficulties arise because visitors are usually unfamiliar
with the control system and critical problems are usually assigned to in-house
staff. However, Fermilab will be much more welcomed at CERN if it can
bring real resources to the table and has the ability to solve
operational problems. One possibility is to develop a suite of software
products to enable Fermilab accelerator physicists to make key contributions to
the beam commissioning of the LHC. This talk will describe possible software
products and a possible organization for developing these products. People who
are willing to work on these projects are encouraged to attend this talk. September 21, 2006 Run II Status and Future Development: Can
We Achieve 8 fb-1 Valeri Lebedev FNAL Abstract Present
status of Run II program and further development aimed to achieve the planned Run
II luminosity integral will be discussed. Recent machine performance assures us
that we can achieve 4-5 fb-1 of integrated luminosity by the end of
FY-2009 with minimum development. However the upgrade path we are currently
pursuing should allow us to achieve 7-8 fb-1. Major contributions
should come from increase of stacking rate in Antiproton source, fast and more
efficient Accumulator-to-Recycler transfers and improvements in Tevatron. September 14, 2006 R & D in RF
Superconductivity at Walter Hartung Abstract A program of research and
development in superconducting radio-frequency cavities at MSU began in the
year 2000. The primary goal is to support the design and construction of
a next-generation superconducting linac for heavy ions, although the technology
is also suitable for protons. A number of prototype cavities have been
designed, fabricated, and tested. These include quarter-wave resonators,
a half-wave resonator, and elliptical cavities. The elliptical cavities
for heavy ions are at 805 MHz, but MSU is also prototyping an elliptical cavity
at 1300 MHz to assist with the Fermilab Proton Driver effort. Two
prototype cryomodules for a heavy ion linac have been designed; the first
(containing 2 multi-cell elliptical cavities) was completed and tested, and the
second (containing a quarter-wave resonator, a half-wave resonator, and 2 superconducting
magnets) is being fabricated. Research is also underway in x-ray imaging
of cavities, heat transfer in cavities, materials and surface studies,
alternative cavity designs, alternative cavity fabrication techniques,
liquid-helium-filled cavities, and other areas. September 7, 2006 RF Breakdown and High Gradient Limits Jim Norem ANL Abstract The
MuCool program has an experimental program to study the problem of maintaining
high gradients in low frequency rf systems, an important constraint on Muon
Cooling. We have also started modeling and material science studies to
support this effort. Initial modeling showed that tensile stresses are
important in breakdown, however we have extended the model to study the
equilibrium that develops between surface damage and structure
performance. Our model seems to be able to calculate all aspects of rf
structure performance, with precision that is limited by a few specific
measurements. The model should apply to some aspects of CLIC and ILC
operation, and a variety of other high gradient systems. Simulation of
transition crossing in the Fermilab Booster Xi Yang FNAL Abstract In
order to build a realistic model for Booster transition crossing, we are updating
a particle tracking code STRUCT to 3-D simulation code by adding a longitudinal
motion model. The model responsible for the beam acceleration includes
space charge effect, Gamma-t transition-jump, and the radial feedback
system. It has been bench marked against the experiment in the charge
transmission vs. the beam intensity and the excitation of bunch length
oscillations after transition. It has been applied to investigate the
influence of radial feedback gain on the charge transmission, energy error, and
beam parameters; the influence of the transition-jump system on the bunch
length and momentum spread at transition; and the influence of the phase-jump
speed at transition on beam parameters. We are in the process of building
a 3-D model for Booster. The History of H- Source Development J. Peters DESY Abstract The rich history of H- source
development is presented highlighting the most successful designs. The
operating principles of the two families of sources, surface (magnetron and
penning) and volume, are explained. Important design principles
and the construction of sources, including several types of discharge chambers
and of hybrid chamber arrangements, will be shown. The optimisation of RF
source-design will be presented, in particular the antenna coupling, the choice
of frequency range, and the design of the extraction plasma region and also the
results of detailed experimental investigations of the plasma parameters with
laser photo-detachment and Langmuir probes. Finally a practically maintenance
free high current RF H- source is presented. Presentation MDI Studies at the ILC and related test
beam program at SLAC's End Station A Facility Michael
Woods SLAC Abstract The
design of the International Linear Collider impacts Detector design and physics
capability beyond the delivered luminosity and energy reach.
Machine-Detector Interface (MDI) work for the ILC includes: I’ll
discuss these MDI aspects for the ILC and related beam tests in the SLAC End
Station A facility. August 17, 2006 Improving the
performance of SRF cavities and other high voltage electrodes by treating the
surfaces with Gas Cluster Ion Beams (GCIB): Can a perfect electrode be
manufactured and tested? David R. Swenson (Epion Corporation) Abstract Gas cluster ion beams (GCIB)
is a new nano-technology that smoothes, etches, and/or chemically alters a
surface by bombarding the surface with an energetic charged particle beam of
cluster ions (~5,000 atoms/cluster). It has drastically reduced DC field
emission of stainless steel electrode material used for high field electron injectors[1].
For SRF cavity surface preparation, GCIB can remove sub-micron scale asperities
[2] and can reduce nano-scale roughness to atomic level smoothness on planar
and non-planar surfaces. GCIB also has the desirable feature that it
is applied under high vacuum conditions so it can be used as the very last
conditioning step before cavity operation. We have studied GCIB
treatments of BCP polished Nb samples using Ar, O2, or O2+NF3 clusters
accelerated with voltages up to 35 kV. The samples have been evaluated
using scanning field emission microscopy (SFEM) as well as AFM, SEM and
SIMS. Etch rates have been measured using a quartz-crystal
microbalance. The measurements show a dramatic and reproducible reduction
in the number of field emission sites on GCIB treated surfaces, and show an
alteration of oxide stoichiometry. We are continuing our investigation of
the effect of GCIB on the grain structure produced by BCP polishing.[2] A
GCIB etch rate of 5 nm cm^2 s^-1 for Nb has been measured using a small-test
stand source, indicating that 50 nm can easily be etched from the entire
surface of a typical cavity in a period of several hours. There are
excellent prospects that the etch rate can substantially increased and Epion
Corporation is developing a beam delivery system for treating the inside of SRF
cavities using GCIB. [1] D.R. Swenson, E. Degenkolb, Z. Insepov, L. Laurent and G.
Scheitrum, Nucl. Instr.
and Meth. B 241 (2005) 641 [2] D.R. Swenson, Presentation Muon Beam
Cooling for Colliders, Neutrino Factories, and Experiments Rolland Johnson (Muons, Inc) Abstract Bright muon beams are needed for muon colliders and are
useful for neutrino factories and new muon decay experiments. A
new technique to achieve very effective six-dimensional (6D) muon
beam cooling is based on a helical cooling channel (HCC) [1] composed of
superimposed solenoidal, helical dipole, and helical quadrupole magnetic fields. The
Muon And Neutrino eXperiment (MANX) which is being designed to demonstrate the
use of this HCC technique will be described as will several complementary
hardware and software innovations and projects [2]. [1] Y. Derbenev and R. P. Johnson; PRSTAB 8,
041002 (2005) http://www.muonsinc.com/reports/PRSTAB-HCCtheory.pdf [2] R. P. Johnson, A Short Overview of Muons,
Inc. Projects and Proposals, http://www.muonsinc.com/reports/Eleven%20Muons,%20Inc.%20projects%20and%20proposals.pdf Presentation August 08, 2006 Operating the D0 Detector Bill Lee (FNAL) Abstract The D0 detector is a general
purpose detector designed to detect signals from a wide variety of physics processes
from proton-antiproton collisions at the Tevatron. In order to to make
the best use of the collisions provided, it is important to keep the detector
in the best possible operating
condition. Detector operations and the challenges of making most efficient use
of the delivered collisions will be addressed. Do we need more accelerator research? - Situation at
Fermilab and highlights from 2006 Advanced Accelerator Concepts workshop Vladimir Shiltsev (FNAL) Abstract I will give a brief overview
of recent developments in advanced accelerator schemes presented at AAC'06 and discuss
whether Fermilab needs to expand beam physics research and possible directions
for that. July 27, 2006 Noise
in RF Systems Ralph Pasquinelli (FNAL) Abstract The basics of sources of noise,
measurement techniques, and effects on RF systems will be covered. Examples on
the importance of selection of components and placement for optimum system
performance will be discussed. Signal to Noise ratios, phase noise,
intermodulation distortion, dynamic range, and a host of other noise related
issues are presented. July 20, 2006 Muon Collider Parameters and Cooling Schemes Robert Palmer (BNL) Abstract Possible parameters for
Muon Colliders of 2, 4 and 8 TeV c of m will be proposed. A cooling scheme will
be presented using a linear cooling lattice, emittance exchange in large radius
helical (Guggenheim) channels, bunch merging in a wiggler lattice, and final
cooling in high filed solenoids. The advantages and disadvantages of some
alternative technologies will also be discussed. Talks
in 2006 Radio Frequency (RF) Systems for the ILC Ralph Pasquinelli (FNAL) Abstract This talks provides some of the basic
principles of RF acceleration and in particular specific details pertaining to
Superconducting RF. How
does a klystron make power? What is the role of the modulator? How does the
power get distributed to the cavities? What happens when the beam is present?
What issues are unique to superconducting RF and to the ILC? Talks
in 2006 July 13, 2006 Introduction to Radio Frequency Fundamentals for Particle
Accelerators Part III David McGinnis (FNAL) Abstract This lecture is intended
to be the first of several lectures that cover basic RF techniques for particle
accelerators. These lectures will cover transmission line theory, load
matching, scattering parameters, and AM and FM analysis of beam signals. The
lectures will also cover RF cavity fundamentals such as cavity modes, loaded
and unloaded Q, input coupling, and cavity measurements such as bead pulls. A
second set of lectures will cover the concepts of spectrum and network analysis,
time domain reflectometry, noise figure measurements, and microwave devices
such as waveguides, directional couplers, and filters. Talks
in 2006 Introduction to Radio Frequency Fundamentals for Particle
Accelerators Part II David McGinnis (FNAL) Abstract This lecture is intended
to be the first of several lectures that cover basic RF techniques for particle
accelerators. These lectures will cover transmission line theory, load
matching, scattering parameters, and AM and FM analysis of beam signals. The
lectures will also cover RF cavity fundamentals such as cavity modes, loaded
and unloaded Q, input coupling, and cavity measurements such as bead pulls. A
second set of lectures will cover the concepts of spectrum and network
analysis, time domain reflectometry, noise figure measurements, and microwave
devices such as waveguides, directional couplers, and filters. Presentation July 13, 2006 Introduction to Radio Frequency Fundamentals for Particle
Accelerators Part III David McGinnis (FNAL) Abstract This lecture is intended
to be the first of several lectures that cover basic RF techniques for particle
accelerators. These lectures will cover transmission line theory, load
matching, scattering parameters, and AM and FM analysis of beam signals. The
lectures will also cover RF cavity fundamentals such as cavity modes, loaded
and unloaded Q, input coupling, and cavity measurements such as bead pulls. A
second set of lectures will cover the concepts of spectrum and network
analysis, time domain reflectometry, noise figure measurements, and microwave
devices such as waveguides, directional couplers, and filters. Presentation Instability
Studies on a Spherical Inertial Electrostatic Confinement Hyung Jin Kim Abstract The
spherical Inertial Electrostatic Confinement (IEC) concept offers an
alternative fusion plasma confinement scheme, where charged particles are
accelerated and confined electrostatically with a series of biased spherical
concentric electrodes. The inertia of the accelerated ions compresses the
ions and builds up the space charge at the center of the cathode grid, creating
a series of deep virtual electrostatic potential wells which confine the ions
into a small volume where an appreciable number of nuclear fusion reactions
could occur. It is very attractive for a power plant due to its
mechanical simplicity and high power-to-mass ratio. It provides a
favorable development path for neutron source. However, various stability
issues must be resolved before reactor feasibility can be established. In
order to evaluate IEC concept, it is essential to develop a reliable and
flexible instability analysis method for equilibrium plasma in a potential
well. As a part of this study, methods are sought to avoid or suppress
any destructive instabilities. Methods to be explored include modification/control
of the well profile, control of the electron to ion beam density ratio, control
of the angular momentum of the beam, etc. For this purpose, a
perturbative (delta-f) particle simulation techniques for a kinetic analysis is
applied to simulate completely the dynamic evolution of perturbed
Vlasov-Poisson equations, and, in addition, to achieve much more accurate
simulations of the nonlinear dynamics using less simulation particles compared
to conventional Particle-in-Cell (PIC) method. This model is used to
study the behavior of two-stream-like instabilities related to the trapped
spherically converging ions. Then, stability of boundaries in various
operating parameter spaces is described. Presentation LHC Quench
Protection & Energy Extraction Systems Bob Flora FNAL Abstract The 10.6 GJ stored in the 27
Km LHC guide field must be managed with some care. This requires very reliable
and accurate quench detection, prompt protection of the quenching elements, and
harmless extraction of the remaining stored energy. An overview including cold
diode technology, contrasts with the Tevatron, and current status of the system
will be presented. June 22, 2006 Introduction to Radio Frequency Fundamentals for Particle
Accelerators Part II David McGinnis (FNAL) Abstract This lecture is intended
to be the first of several lectures that cover basic RF techniques for particle
accelerators. These lectures will cover transmission line theory, load
matching, scattering parameters, and AM and FM analysis of beam signals. The
lectures will also cover RF cavity fundamentals such as cavity modes, loaded
and unloaded Q, input coupling, and cavity measurements such as bead pulls. A
second set of lectures will cover the concepts of spectrum and network
analysis, time domain reflectometry, noise figure measurements, and microwave
devices such as waveguides, directional couplers, and filters. Presentation Valeri Lebedev (FNAL) Abstract Presentation
Introduction to Radio Frequency Fundamentals for Particle
Accelerators David McGinnis (FNAL) Abstract This lecture is intended
to be the first of several lectures that cover basic RF techniques for particle
accelerators. These lectures will cover transmission line theory, load
matching, scattering parameters, and AM and FM analysis of beam signals. The
lectures will also cover RF cavity fundamentals such as cavity modes, loaded
and unloaded Q, input coupling, and cavity measurements such as bead pulls. A
second set of lectures will cover the concepts of spectrum and network
analysis, time domain reflectometry, noise figure measurements, and microwave
devices such as waveguides, directional couplers, and filters. May 25, 2006 US-LHC Activities
in the Accelerator Division (FNAL) Abstract The US LHC Accelerator
Research Program (LARP) continues the involvement of the major I will review recent
progress and highlight some accomplishments. Opportunities for involvement in
machine studies at CERN and LHC commissioning will be discussed. Presentation
Status of Slip
stacking in the Kiyomi Seiya (FNAL) Abstract Slip stacking for pbar
production has been operational since December 2004 and increased the beam
intensity on pbar target more than 60%. We plan to use slip stacking schema for
NuMI neutrino experiment for increasing proton intensity on NuMI target by
about a factor of two in a 2.2 sec MI cycle. We are going to discuss about
technical issues for multi-batch slip stacking. Presentation Ion Source Choices An H- source for the High Intensity Neutrino
Source Doug Moehs (FNAL) Abstract The
High Intensity Neutrino Source (HINS) program at Fermi National Accelerator
Laboratory aims to develop a multi-mission linear accelerator (LINAC) designed
to accelerate H- ions to 8 GeV, delivering up to 2 MW of beam to the
Main Injector. Initial acceleration (50 keV to 2.5 MeV) is achieved by
mean of a Radio frequency Quadrupole (RFQ). The acceptance parameters of
the RFQ establish constraints on the ion source and low energy beam transport
(LEBT) system. In this talk, I will discuss the ion source selection
process and present the ion source choice for the HINS test facility. I
will also summarize the work that is currently being done at Fermilab to
prepare this source for operation later this year.
Presentation DARHT - A Unique Accelerator Facility
Supporting the Robert W. Garnett (LANL) Abstract Presentation Electron Cloud
Simulations for the LHC and Main Injector Miguel Furman (LBL) Abstract We present assessments of
the electron-cloud density in the LHC and Main Injector, arrived at through
computer simulation. The LHC beam is simulated through the expected range
of operation, producing estimates of electron cloud density and of the power
deposited in the cryogenic system by the cloud. The Main Injector is
simulated for its current typical beam, as well as that which would be gained
from an injector upgrade to a superconducting linac. Presentation Tune and
Chromaticity Tracking in the Tevatron Cheng-Yang
Tan FNAL Abstract The Tevatron tune tracker
has been commissioned and operational since Sep 2005 and has been tracking the
betatron tunes of all stores until the shutdown. We will discuss how the
tune tracker works and compare some of the store data. A chromaticity tracker has
been proposed which uses a novel technique invented by D. McGinnis which works
in synergy with the tune tracker. We will show some preliminary results
using this technique. Presentation Solenoids for
Focusing Proton Beams – Status of R&D at FNAL Iouri Terechkine FNAL Abstract For any high power linac,
keeping beam loss at low level constitutes one of key requirements. Partial
solution to the beam loss problem can be provided by slowing down beam
emittance growth rate in the linac’s front end. Using solenoids for beam
focusing at this stage suggests one of the ways to achieve this goal. For high current,
superconducting RF linacs, the requirement of having very low magnetic field on
surfaces of RF cavities made of Niobium coexists with the requirements of
having relatively small focusing period and significant focusing strength. This
makes development of this focusing system somewhat challenging. This report
describes the approach used at Fermilab while developing a focusing system for
the front end of a 40-mA H^- linac. Presentation ILC collimation,
background and extraction line studies at RHUL/JAI Ilya Agapov (RHUL/JAI) Abstract The Royal Holloway
University of London team has been involved in background and collimation work
for the ILC in the past several years. We have developed a simulation tool
based on Geant4, BDSIM, which has been used for background evaluation in beam
lines and other tasks. An extensive benchmarking and cross-checking program is
currently underway with the FNAL team. Here we present simulation results on
the ILC collimation system, Machine-Detector Interface and extraction
lines. Presentation April 18, 2006 CHROMATICITY AND
IMPEDANCE EFFECT ON THE TRANSVERSE MOTION OF LONGITUDINAL BUNCH SLICES IN THE
TEVATRON Vahid Ranjbar FNAL Abstract The Transverse turn-by-turn
evolution of a bunch slice is examined considering chromatic and impedance
effects. A multi-particle simulation is used to fit Impedance and second order
chromaticity to by comparing the beam evolution over 1000 turns with our model. Presentation Antiproton Source
Studies and Stacking Keith Gollwitzer FNAL Abstract Two
study periods for the Antiproton Source were precipitated by the unfortunate
failures in the Tevatron. Even before the failures, plans were made for a study
period due to the availability of upgraded instrumentation and orbit control.
There were further stacking studies after the second study period which led to
the improvement in the antiproton stacking rate during the last month of
running. The work leading up to the studies period, the studies performed, and
the increase in stacking rate will be discussed. Presentation Coherent
transverse electron-antiproton instability in the Recycler Ring Alexey Burov FNAL Abstract Lifetime degradation of
electron-cooled ions was observed at several electron coolers. In the Recycler,
both the lifetime drop and emittance growth of the e-cooled pbars are seen. A
possible reason for that can be a coherent interaction between the electron and
antiproton beams. A theoretical model of this instability is presented, and a
practical recommendation for its suppression is explained and discussed. Presentation ILC Accelerator R&D at Fermilab Shekhar Mishra FNAL Abstract Presentation Designs and
optimization for a series-fed, broadband impedance-matched, end-fire linear
antenna array Zhentian Xie Abstract The
main goal of this research is to obtain input impedance matching over a wide
range of frequencies for a linear array of antennas. The basic structure of the
array is to connect element antennas connected with quarter-wavelength
transmission lines. The motivation for studying this structure is that broad
matching bandwidth along with an end-fire radiation pattern might be achieved
by using the maximums bandwidth (MBW) algorithm. In theory, assuming that a
dipole antenna in an antenna array is represented by an RLC circuit, the dipole
array can be represented as an impedance network. The impedance network could
show that a wide bandwidth along with a high gain of the antenna may be yielded
by tuning out the inner resonant characteristics of the resistor network.
Numerical Electromagnics Code (NEC2) is used to simulate thin-wire dipole
arrays. The matching performance of a thin-wire dipole array may be optimized
by adjusting certain parameters of the dipole arrays, such as the length of the
dipoles, the characteristic impedances of the transmission lines, the length of
the transmission lines, and relative tuning of element antennas. To achieve the
desired bandwidth and radiation pattern, the optimization of the antenna array
widely depends upon the genetic algorithm (GA), and on the Butterworth,
equi-ripple and Chebyshev design algorithms. Some antenna arrays will be
designed and tested by using the optimized parameters. According to the
different definitions of the fitness functions and bandwidth, several simulation
results show that the bandwidth can be broader after the genetic optimizations,
while the designed reflection coefficients are much flatter or lower in a large
frequency range. Dipoles
on twin rods with microstrip transmission lines were explored. Compared with
Yagi-Uda array designs, these dipole arrays showed improvements on matching
performance. Presentation Analytical
Approach to Eigen-Emittance Evolution in a Storage Ring Boaz Nash SLAC **Note Location Changed ** **Location Curia II** Abstract Analytical Approach to
Eigen-Emittance Evolution in a Storage Ring I discuss a general approach
to computing the beam evolution in a weakly coupled linear storage ring with a
small damping/diffusion effect. I describe a perturbation theory
formalism for finding the global invariants near linear resonances in the
presence of weak coupling. These invariants are combined with a local
stochastic process to find the emittance evolution. For the case of
synchrotron radiation, this reduces to the familiar results of Sands in the
uncoupled case. We apply our perturbation theory to several cases
including synchrobetatron coupling caused by a crab cavity, a case of current
interest. I also discuss the inclusion of intrabeam scattering within
this framework and some resulting insights. Presentation Entry of Solids into Liquids Torben Grumstrup Abstract M.
Worthington in the late 19th century studied how liquid drops and solid objects
entered into liquid pools. He used a clever illumination system to take
photographs of "entry" phenomena such as splashes, jets, and
cavities. Presentation Talks
in 2006 March 21, 2006 Numerical modeling of
novel electron materials and devices Sebastian Beysserie IIT Abstract Presentation Interfacial
FRACture Testing to invesitgate the Mechanics of sofc interconnect alloy
durability Nandhini Dhanaraj M.S. Mechanical Engineering Abstract This
research work investigates the fundamental thermo-mechanical aspects of the
durability of solid oxide fuel cell (SOFC) interconnect alloys. A key failure
mechanism for interconnects is the spallation of the chromia scale that forms
on the alloy, as it is exposed to fuel cell environments at operating temperatures.
Indentation testing methods were formulated to measure critical energy release
rate (Gc) associated with the spallation of chromia scale/alloy
systems, as well as the methods for analyzing the tests to determine the Gc
of the interface between the scale and substrate. Experimental results were
obtained for the Gc of interfaces between ferritic interconnect
alloys and grown chromia scales. Results from specimens subjected to simulated
SOFC environments are used to understand the mechanisms leading to scale
spallation and the effects of different environments on scale/alloy durability.
Results from short-term exposure indentation tests are related to results from
longer-term exposure TGA experiments carried out at the Presentation ACNET vs EPICS at
Fermilab Sharon Lackey (FNAL) Abstract An
overview of the Experimental Physics and Industrial Controls System (EPICS) and
a comparison of it’s features with the ACNET Controls System which is
used presently to control the Fermilab accelerator
complex. The plans for EPICS use at Fermilab and the
planned improvements for Version 4.0 of EPICS will be highlighted Presentation Overview of
Tevatron Operations Ronald Moore (FNAL) Abstract Running the Tevatron at a consistently high
performance can be a challenging task, because so many things have to work
right. I will present an overview of a Tevatron shot-setup and store,
focusing on operations and improvements over the past year. I will also
discuss on issues and work to be done during the shutdown. Presentation Low Emittance
Electron Beam Studies Rodion Tikhoplav (UCLA) Abstract We present a study of
transverse emittance versus the shape of the photocathode drive-laser pulse.
For that purpose a special temporal profile laser shaping device called a
pulse-stacker was developed. We also discuss longitudinal beam dynamics studies
using a two macro-particle bunch; this technique is helpful in analyzing pulse
compression in the magnetic chicane, as well as velocity bunching effects in
the rf gun and the accelerating 9-cell cavity. Such beam studies are
necessary for fixing the design of new Linear Colliders as well as for the
development of Free Electron Lasers. Presentation Discovery and
Mitigation of the Electron Cloud at KEK Kazuhito Ohmi (KEK) Abstract The electron cloud effect in
positron ring is discovered at KEK-Photon factory in 1995. The effect should occur and
make problems in every high intensity positron (proton) ring. Therefore the effect have
been studied at KEKB as well as we can, because KEKB-Low Energy Ring was
designed as the highest intensity positron ring. We review the electron cloud
instability observed in KEK-PF and KEKB, and history of the progress of KEKB
against the electron cloud. Electron cloud effect in
J-PARC is also discussed. TeVnet: Surveying the Big Machine John Greenwood **Note Location Changed ** **Location Curia II** Abstract TeVnet
is a precise surveying reference frame that was devised to remedy alignment
issues within the Tevatron accelerator. This presentation details the planning,
preparation, implementation, and analysis of this effort. The Tevatron
Alignment Committee requested a one-sigma precision of diametrically opposite
points to be better than 2.5mm. The precision of the delivered results
was below 1.0mm. Computational models, algorithms and
computer codes in accelerator physics Valentin Ivanov (SLAC) Abstract Physical
electronics researches the patterns of charge particle behavior in
electromagnetic fields. The parts of this science are vacuum electronics,
plasma physics, solid-state physics (semiconductor micro electronics) and non
linear optics (laser physics). We will focus on the vacuum electronics
(electron optics) mostly and on the beam-surface and beam-plasma interactions.
The variety of physical models in vacuum electronics predetermines the
substantial differences for the mathematical formulations and methods for
solving this class of problems. In the absence of the explicitly defined
regulating parameters for the ensembles of charged particles the most effective
approach consists of using the Vlasov’ or Fokker-Plank equations for
6-dimensional distribution function. Most popular method for the regular
structures (beams and bunches) is a trajectory approach, but in the presence of
small physical parameters – aberration approach. Monitoring Abort
Gap Beam Intensity in the Tevatron Using Synchrotron Radiation Randy Thurman-Keup (FNAL)
Abstract During operation of the
Tevatron in colliding beam mode, a small amount of the beam diffuses out of the
bunches and spreads around the ring. The presence of this beam in the abort gap
can have a serious effect on superconducting magnets and a devastating effect
on the silicon detectors of CDF and D0. During an abort, the kicker magnets
ramp up during the abort gap. Beam passing through the kickers while they are
ramping sprays into magnets and into the silicon detectors. I will present an
overview of the system that monitors the intensity of the abort gap beam using
synchrotron radiation emitted near the edge of a Tevatron dipole magnet. Presentation FZJ
superconducting RF Cavities Forschungszentrum Juelich (Research Center Juelich)
Presentation
Condensed matter physics experiments relevant to accelerator development
Université de Genève, Switzerland
Twisted Waveguide Accelerating Structures: Potential and Challenges
University of Tennessee - Knoxville
Traditionally, slow wave structures are constructed by employing reactive loading such as a periodic iris or
a dielectric load. However, most practical systems use the periodic corrugation of the waveguide wall. On the
contrary, the slow-wave nature in the twisted waveguide structures originates from the fact that the wave path
could be elongated by twisting the waveguide, so the fast electromagnetic wave is actually travelling along a longer
spiral path, while the slow particles are traveling along a straight path. Controlling the spiral path through the
twist-rate can force the longitudinal velocity matching between the electromagnetic wave and the particles.
The conventional multi-cell cavity-based accelerator structures (for instance TESLA-type cavity) have
a transverse cross-section that is continuously changed along the acceleration path. The non-uniform transverse
cross section is the main reason for the expensive cost and the possibility of serious trapped modes phenomena
happens in these cavity-based accelerator structures. On the contrary, the twisted waveguide structures have
a uniform transverse cross section throughout the acceleration path which potentially eliminates the troubling
trapped modes inside the twisted waveguide structures, offering better field uniformity along the acceleration
path and so enhancing the beam stability. Unlike the periodic coupled cavities, the dispersion relation of the
twisted structures is similar to that of regular hollow waveguides.
To build a practical accelerating cavity structure using the twisted waveguide, more development work is
needed: cavity structure tuning, end wall effects, incorporating beam pipes and input power couplers, and
HOM damping, etc.
In this talk, the practical aspects of making more complete twisted waveguide accelerating structures are
discussed with the results of computer simulations along with the latest experimental results that have been carried out in SNS.
Presentation
Design of an SDD-based Gamma Camera: detector, front-end and signal processing
Politecnico di Milano
Presentation
Design and Development of the T2K Pion Production Target
Science & Technology Facilities Council, Rutherford Appleton Laboratory, UK
Project X Strategy and Status: A Discussion
FNAL
Analysis of the Transient Natural Convection Driven by Energy Deposition inside High-Pressure RF Cavities
Muons, Inc.
The outline for Lecture 2 is:
Accelerator Physics Developments for Tevatron Run II:
Lecture I, part 2: Linear optics fundamentals and linear optics with coupling
between degrees of freedom
FNAL
The outline for Lecture I is:
Accelerator Physics Developments for Tevatron Run II:
Lecture I: Linear optics fundamentals and linear optics with coupling between
degrees of freedom
FNAL
The outline for Lecture I is:
What happens in a gas filled RF cavity when beam goes
thru it?
FNAL
Status of the cavity BPM developments at KNU and
Fermilab
FNAL
Basic R&D for High gradient ILC SC cavity in
KEK-STF
KEK
Power network distribution for IC designs and its
challenges in deep submicron technologies
University of California at Santa Barbara
Using Hardware-in-the-Loop Simulations to improve EPA
Emissions Testing
The Cooper Union
Experience with the Commissioning of the LHC
Superconducting Magnets
FNAL
Presentation
XFEL Module Assembly at CEA-Saclay
CEA-Saclay
Nuclear Applications of Accelerators; Experience in
the 'A' Programs (APT, ATW, AAA, AFCI)
LANL
The European XFEL
DESY
A Novel
Tele-Manipulation for Cell Injection
University of Kansas / Korea University of Technology
In this presentation, I will give a brief introduction about the design,
simulation and development of a novel tele-robotic system. A visual feedback
and haptic force feedback techniques for cell injection process will also be
presented and discussed. The goals of this proposed effort were to overcome
problems related to manual operations for micro-cell injection applications.
This research work will have immediate applications in the biological cell
injections, drug delivery applications and various medical applications.
Superconducting
Transition Edge Sensors
NIST
Ground Motion Studies
at Fermilab
FNAL
High intensity ring physics
and technology at SNS
Oak Ridge National Lab
Presentation
Head-Tail Modes for
Strong Space charge
(in
two parts)
FNAL
Two Devices for HINS
FNAL
Cancelled!
Precision Beam
Measurements Using Accelerating Cavities
SLAC
particles are known to support many different modes of electromagnetic
oscillation in addition to the fundamental, accelerating, mode. It is
well known that these parasitic, or Higher Order Modes (HOMs), may
strongly degrade the quality of the beam, and limit the performance of
the accelerator, so they are normally thought of as something that
should be avoided and suppressed by suitable design of the machine.
This talk discusses work done to demonstrate the positive contribution
these modes can make to the performance of the machine by providing
multiple, high resolution, beam trajectory measurements, as well as
information on the alignment of the accelerating cavities, and the phase
stability of the acceleration system.
A brief overview of the physics of
description of the experiment performed at the FLASH light source in
DESY,
Presentation
Permanent Magnet work at Fermilab 1995 to Present
Fermilab
XFEL and Collaboration with ILC SCRF
(Special Seminar)
DESY
Proton Source for HINS First Tests
Fermilab
Presentation
Alternative Project X configuration
Fermilab
The future of accelerator-based high energy physics at Fermilab relies on
the construction of a high intensity proton source. Most proton sources
consist of a linac feeding a rapid cycling synchrotron. The performance of
these sources is a compromise between the space-charge tune shift
limitations at injection into the synchrotron and the high cost of RF power in
the linac. The advent of superconducting RF holds the promise of making a
high power linac more affordable. By blending the performance of a
superconducting linac with the energy range of a synchrotron, a very
flexible and cost-effective proton source could be realized. This proton
source could be built in stages. The construction of a project in well
defined stages in which at the end of every stage a substantial increase in
performance is obtained is very attractive in these times of tight budgets.
This talk will examine the parameters and staging of such a source.
The ICD, a first step towards the Intensity Frontier
Fermilab
We have developed an initial configuration for the Steering group path to the
intensity frontier. It consists of an 8 GeV superconducting linac, the
Recycler, and the Main Injector. I will describe the configuration, the
reasoning, and the first thoughts on the plan.
Quench Limit Simulations and Measurements for Steady State
Heat Deposits in LHC Magnets
CERN
A quench, transition of a conductor from the superconducting to the normal
conducting state, occurs irreversibly in accelerator magnets if one of the
three parameters: temperature, magnetic field or current density, exceeds a
critical value. Energy deposited in the superconductor by the particles lost
from the beams, provoke quenches detrimental for the accelerator operation.
A Network Model is used to study of the thermodynamic behaviour of the LHC
magnets. The results of the heat flow simulation in the magnets with the
network model were validated with measurements performed in the CERN magnet
test facility. A steady state heat flow was introduced in the coil by using
both the quench heaters implemented in the LHC magnets and a dedicated internal
heating apparatus installed inside cold bore. The heat loads from these heat
sources needed to initiate quenches as a function of the coil current are
calculated from the Network Model and compared to the settings leading to
quench occurence.
Presentation
Can we increase the operating gradients of linacs?
Argonne National Laboratory
Recent developments in modeling high gradient behavior in rf structures, and
new techniques in controlling the chemistry and morphology of surfaces seem to
open the possibility of operating rf systems at higher gradients than are
presently achieved. The talk will review new developments in modeling and new
ideas on surfaces compatible with high gradients.
Limits and Prospects of Nb3Sn Accelerator Magnets
Sant'Anna School (Pisa) and Fermilab
Future upgrades of machines like the LHC at CERN require pushing accelerator
magnets beyond 10 T. Larger magnet sizes and more performing superconductors
introduce additional challenges. This work improves existing analytical models
of the magnetic field and stress of dipole and quadrupole sector windings,
addressing how far the engineering of High Field Magnets can be pushed.
Problems and limitations of Nb3Sn magnets are identified by correlating the
field intensity and the loss of field quality to the magnetic and mechanical
properties of the material.
Statistical Data Analysis
A tutorial in two parts
Fermilab
The complexity of instrumentation sometimes requires data analysis to be done
before the result is presented to the control room. This tutorial reviews some
of the theoretical assumptions underlying the more popular forms of data
analysis and presents simple examples to illuminate the advantages and hazards
of different techniques.
Cryogenics for Warm Physicists and Engineers
Fermilab
Warm people (as opposed to cryogenic experts) whose project includes cryogenics
will find it useful to have some familiarity with a few of the basic principles
and common standard practices in cryogenics. These include methods of
refrigeration, heat transport modes, piping stability, and safety and
compliance issues. Common cryogenic system components, such as lambda plugs,
Kautzky valves, bayonets, and wet engines are described, and some mysteries of
cryogenics at Fermilab are explained.
High Gradients and RF Power Generation at the Argonne
Wakefield Accelerator Facility
Argonne National Laboratory
The Argonne Wakefield Accelerator Facility (AWA) is dedicated to the study of
electron beam physics and the development of accelerating structures based on
electron beam driven wakefields. In order to carry out these studies, the
facility employs a photocathode RF gun capable of generating electron beams
with high bunch charges (up to 100 nC) and short bunch lengths. This high
intensity beam is used to excite wakefields in the structures under
investigation. The wakefield structures presently under development are
dielectric loaded cylindrical waveguides with operating frequencies of 8 -15
GHz, in which gradients of 100 MV/m have been reached. Similar structures have
also been used as RF power sources, driven by single electron bunches or bunch
trains of up to 16 bunches. Other important experiments, at different RF
frequencies and using planar or cylindrical geometries, have been carried out
at various other facilities. A number of new experiments are planned in the
near future to explore the capabilities of this class of structures. This
presentation will provide an up-to-date survey of the activities in this area
of research.
Evolutionary Optimization Methods for Accelerator Design
Michigan State University
Many problems from the fields of accelerator physics and beam theory can be
formulated as optimization problems and thus can benefit from modern
optimization techniques. However, the use of such techniques in these fields is
so far rather limited. Relatively new and actively developed Evolutionary
Algorithms (EAs) for optimization possess many attractive features such as:
ease of implementation, modest requirements on the objective function, good
tolerance to noise, robustness and the ability to efficiently perform a global
search. These make them the tool of choice for many design and optimization problems.
We present several different problems of accelerator design and demonstrate how
they can be treated by EAs.
Impressions from the Beam Instrumentation Workshop BIW08
Randy Thurman-Keup
Manfred Wendt
Fermilab
Highlights from the Beam Instrumentation Workshop (BIW08) will be shown.
Tevatron Fixed Target Redux and the NuSOnG Proposal
Janet Conrad, Columbia University
A proposal for a new Fermilab neutrino experiment, NuSOnG, is discussed. The
experiment utilizes the 800 GeV fixed target capabilities of the Tevatron and
the beam intensities commensurate with the Main Injector to make precision
electro-weak measurements at the Terascale. This talk briefly describes the
experiment and also discusses the issues with resurrecting fixed target
operation of the superconducting synchrotron.
The MERIT Experiment: a Proof-of-Principle Demonstration of a
Mercury Jet Target for Megawatt Proton Beams
The MERIT experiment was designed as a proof-of-principle test of a target
system based on a free mercury jet inside a 15-T solenoid that is capable of
sustaining proton beam powers of up to 4MW. The experiment was run at CERN in
the fall of 2007. This talk describes the background of this experiment,
the results of the tests and their implications for new facilities
including a muon collider.
Project X and the Future of the Fermilab Accelerator Complex
Project X represents a world-leading multi-MW proton facility at Fermilab, with
strong technology connections to linear collider and muon based facilities.
This talk will describe the concept and performance goals for Project X, the
proposed R&D program, and its role in possible long term evolution of the
Fermilab accelerator complex.
Tevatron Integrated Luminosity: A tutorial primer
Recent record-setting performance of the Fermilab Tevatron is the culmination
of a long series of efforts to optimize the many parameters that go into
generating particle collisions for the colliding beams experiments. The
instantaneous luminosity is determined by the number of particles in each beam,
the physical extent of the beams at the collision point, and the bunch
collision frequency. Meanwhile, the integrated luminosity also depends
upon the rate at which particles are lost due to collisions or other means, as
well as the rate at which the initial store luminosity can be restored after
the end -- intentional or otherwise -- of the previous store. Here we
take an analytical approach in an attempt to illustrate the most fundamental
aspects of integrating luminosity in the Tevatron. The essential
features, including recent values of the weekly integrated luminosity, can be
understood in a transparent way from basic operational parameters such as
antiproton accumulation rate and beam emittance growth rate in the Tevatron.
Operational considerations as the Tevatron operates at or near the
``beam-beam limit'' are also discussed.
Nb3Sn accelerator magnet R&D and LHC
luminosity upgrades
Nb3Sn accelerator magnets advance machine operation fields above 10
T and increase operation margins. Fermilab is working on the development of Nb3Sn
accelerator magnet technology in collaboration with BNL and LBNL. These efforts
are being coordinated in the framework of US-LHC Accelerator Research Program
(LARP). A first step of this R&D includes the demonstration of the main
magnet parameters (maximum field, quench performance, field quality, etc.) and
their reproducibility using series of short models. Then technology scale up is
performed using long coils. The status and main results of the Nb3Sn
accelerator magnet development at Fermilab (both LARP and core program) will be
presented and discussed.
The primary goal of this work is the development of large aperture
high-performance Nb3Sn quadrupoles for the LHC luminosity upgrade.
At present the upgrade is planned in two phases with the target luminosity for
Phase I of ~2.5∙1034 cm-2s-1 and up to
1035 cm-2s-1 for Phase II. In Phase I the
baseline 70-mm NbTi low-beta quadrupoles will be replaced with larger aperture
NbTi magnets and in Phase II with higher performance Nb3Sn magnets.
Recent progress in Nb3Sn accelerator magnet R&D suggests the
possibility of using Nb3Sn quadrupoles in the Phase I upgrade,
improving the LHC performance and providing an early demonstration of Nb3Sn
magnet technology in a real accelerator environment. Possible hybrid optics
layouts for Phase I upgrade with both NbTi and Nb3Sn quadrupoles,
magnet parameters and issues related to using Nb3Sn quadrupoles as
well as possible transition scenarios to Phase II will be also presented and
briefly discussed.
High-resolution surface inspection camera for superconducting
RF cavities
High-resolution surface inspection camera could show ever
undiscovered defects where T-mapping and/or passband
mode measurements suggested abnormalities.
The system will be explained together with recent observations.
Our recent activities will be presented briefly as an introduction.
A New Vision for the Evolution of Controls
With Fermilab's thrust for new accelerator initiatives, the control system for
the accelerator complex will have to be functional well past 2010. It will need
to evolve to meet the new demands and keep up with technology. The Fermilab
Controls Department has initiated this evolution by writing the requirements
for the future control system. In this talk, we will explain the motivation and
the requirements process. We will present some of the ideas for the new
controls, and a plan for the next steps.
Superconducting Strand and Cable R&D for Future
Accelerators
Advanced Accelerator R&D at the A0 Photoinjector
Improvements in Antiproton Cooling and Stacking
Production, transport and laser trapping of radioactive
francium beams for the study of fundamental interactions
Talks in 2007
LHC Interaction Region Upgrade
Beam Loss and Collimation at the LHC
High-power RF sources and components for linear colliders
Optical Stochastic Cooling experiment plans at MIT/Bates and
Prospects of OSC at the Tevatron
OSC formalism (Chris Tschalaer)
Superfast optical parametric amplifier (30 ps) allows small-angle,
longitudinally "rigid" particle bypass. Longitudinal coherence is
achieved with much looser tolerances for bypass magnets. Amplifier output power
of 20 W available shortly achieves 2 hour
cooling time.
Bates OSC experiment (Bill Franklin)
First ever OSC demonstration with 300 MeV Bates electron ring. Short
cooling times (sec) allow "real-time" tuning. Development of
OSC diagnostics and beam control.
Optical parametric amplifiers for Bates and Tevatron (Aleem Siddiqui)
Development of amplifiers with 20-100 W average output power.
Technical concept for Tevatron cooling (Fuhua Wang)
Undulator and bypass in a Tevatron straight section. Simultaneous cooling
of protons and antiprotons. Concept for cooling radially distributed
proton bunches.
Monolithic Signal Processing for Radiation Detectors: late
developments at BNL
Magnet Reliability in the Fermilab Main Injector and
Implications for the ILC
Current graduate student research in accelerator physics at
IIT
Experiments on deflection of charged particles in Japan for
ILC and J-PARC
Modeling Breakdown in Metallic Structures
Peter Stoltz, Tech-X Corp.
Superconducting Multi-Spoke-Loaded Accelerator Cavities
Summary of SRF Materials Workshop held at Fermilab 23-24 May
2007, and SRF Materials Outlook
Exploration of Spin Resonances with Dual Partial Siberian
Snakes in the AGS
TMCI
REVEALED BY FREQUENCY ANALYSIS
OF HEADTAIL TRACKING DATA USING SUSSIX
acceleration of high intensity beams in the CERN PS.
Therefore, the longitudinal emittance must be increased in a controlled
way to avoid beam losses due to instabilities. The higher harmonic 200
MHz RF system (six cavities) used for these blow-ups has to generate a
total RF voltage which, for the most demanding blow-up, is comparable to
the voltage of the principal RF system. After an introduction to the
CERN PS Complex and the RF manipulations needed to produce beams for the
LHC and for the anti-proton decelerator (AD), measurements and
simulations of the longitudinal blow-up are presented.
Several options for a luminosity upgrade based on Nb-Ti "long"
quadrupoles have been studied in the past years. In this seminar we present a
parametric study aiming at finding the relations between the triplet length,
its aperture, and the minimum beta functions that can be achieved in the IP
using quadrupoles built with the LHC main dipole cable. We carry out the
electromagnetic design for apertures ranging from 100 to 140 mm, extending the
results of previous work, and using the critical currents as measured in the
LHC cable production. Issues related to forces and protection in these large
aperture magnets are presented.
We then consider the hypothesis of a phase-one upgrade, where the detectors are
not modified, and therefore the maximal goal is to double the luminosity or to
allow a recovery from non-nominal parameters using stronger focusing. We show
that a solution with 130 mm aperture and 34 m long triplet (i.e., 10 m longer
than nominal) would allow reaching a beta function in the IP of 25 cm. This
would also leave some clearance for removing the limitations in beam intensity
due to the impedance of collimators. Finally, we show that this additional
clearance also allows improvement of the field quality, thus reducing the
nonlinearities arising from the large beta functions.
System Overview for the Multi-element Corrector Magnets and
Controls for the Fermilab Booster
Fermilab is currently constructing a 65 MeV H- Linac. This is an R&D
project demonstrating the feasability of a new type of Front End for an 8 GeV
superconducting Linac, which could deliver beam to the Fermilab Main Injector.
Since the Linac and Main Injector will operate at different frequencies,
approximately 1 of every 6 linac bunches (at 325 MHz) will need to be removed,
in order to avoid losses in the Main Injector, which operates at 53 MHz. For
this purpose, we are in the process of designing and fabricating a chopper
which will apply an electrostatic kick to bunches in the 2.5 MeV MEBT section
of the Linac. We discuss the design parameters for the chopper, the design and
prototypes of the travelling wave meander structure which will apply the kick,
and progress on the fast, high power pulser which will supply pulses to the
chopper structure.
The main objective of this work is to
demonstrate the validity of a Poisson Particle-Particle--Particle-Mesh (P3M)
coupled with a Brownian Dynamics (BD) engine simulation tool in modeling charge
transport in biological ion channels. The challenges of ion channel modeling
are presented with the underlying physical considerations. The details of
the P3M force field scheme and its implementation are presented. The
BD algorithm and the various integration schemes for the particle dynamics are
presented and compared. The numerical model proposed for the electrolyte solution,
the membrane and the ion channel are discussed. A set of benchmarks are
defined and motivated to validate the numerical representation of the
system. Analytical models are proposed for the electrolyte solution in
bulk and interfacial conditions: the Hypernetted Chain (HNC) approximation is
used in conjunction with the Ornstein-Zernike integral equation theory to
describe the electrolyte solution, and provide a comparison with the simulation
results. Similarly, the Gouy-Chapman Double Layer (DL) theory is used to
compute analytical benchmarks for the membrane-solution interface simulation.
The P3M BD simulation of bulk electrolyte solutions and
membrane-solution interfaces is validated by comparison with the proposed
analytical benchmarks. The range of valid numerical parameters for the system
is determined by defining and applying an error analysis methodology.
Subsequently, the well-studied OmpF porin channel from bacterium E. Coli
is used as a test case to validate the proposed charge transport simulation
approach. Potential mapping of the pore is performed for different ion types.
Dynamic charge transport simulations are performed, and macroscopic channel
conductance values are extracted and compared with published experimental
measurements as well as other numerical models. The applicability of the P3M
BD simulation is discussed, and compared with other numerical models from the
computational cost standpoint. Finally, ways to improve the algorithmic
efficiency and accuracy of the simulation are introduced.
Neutrino physics has become increasingly interesting to the high-energy
physics community, as it may provide clues to new physics beyond the standard
model. The physics potential of a Neutrino Factory, a facility to produce
high-energy, high-intensity, high-brightness neutrino beams from decays of
muons stored in a muon storage ring, is thus very high. There has been a global
R&D effort aimed at a Neutrino Factory design that meets the physics
requirements and addresses the key technologies, such as targetry, muon
ionization cooling and acceleration. In this presentation, I will give a
brief introduction on R&D programs under the US Neutrino Factory and Muon
Collider Collaboration (NFMCC), muon ionization cooling channel, international
MICE experiment, with emphasis on high gradient normal conducting RF cavity
R&D for muon ionization cooling channel, explain RF challenges for cavity
design, fabrication, and operation for the muon cooling channels.
Particle physics collider experiments at the high energy frontier are being
performed today and in the next decade in increasingly harsh radiation
environments. While designing detector systems adequate to these conditions
provides a challenge in itself, their safe operation relies heavily on fast
beam monitoring systems using novel radiation hard technologies to protect
these expensive devices from beam accidents. The talk will present a beam
condition monitoring (BCM) system based on polycrystalline chemical vapor
deposition (pCVD) diamond sensors designed for the Collider Detector at
Fermilab (CDF) experiment operating at Fermilab's Tevatron proton-antiproton
synchrotron. We report our operational experience with this system which was
installed in spring of last year. The system currently represents the largest
of its kind operated at a hadron collider and is similar to designs being
pursued by the next generation hadron collider experiments at the Large Hadron
Collider (LHC).
Fast beam phase space cooling is an essential requirement for a muon
collider. The only practical method for muon beam cooling is Ionization
Cooling (IC), in which muons lose all components of momentum by ionizing an
absorber material but only the longitudinal momentum is replaced by RF
cavities. This reduces the angular spread of the beam to the point that heating
from multiple /Coulomb scattering exactly opposes IC. This technique only
cools transversely; to cool the longitudinal emittance it must be exchanged
with the transverse emittance where ionization cooling is effective. A helical
cooling channel (HCC) is made with a special magnetic field formed by helical
dipole and quadrupole magnets combined with a solenoidal magnet to provide this
emittance exchange using a continuous homogeneous absorber.< SPAN
style="mso-spacerun: yes"> New magnet inventions and old precooling
concepts have inspired a practical cooling channel, which has exceptional six
dimensional emittance cooling. I will describe the current status of the HCC
simulation studies and discuss MANX, a proposed HCC experiment.
Coherent instabilities at the FNAL Booster
Fermilab Alignment & Metrology Group
Evgeny Zaplatin