Protons at 8 GeV from the Booster are
injected into Fermilab's Main Injector. They are accelerated to 120 GeV for
fixed target operation or 150 GeV for injection into the Tevatron.
Antiprotons at 8 GeV from either the
Accumulator or the Recycler are accelerated to 150 GeV in the Main Injector and then
injected into the Tevatron.
The Main Injector replaced the Main
Ring in 1998. It ushered in a new era in the physics program at Fermilab.
Physics capabilities were dramatically increased in two ways:
By increasing the beam current, the
reliability and the cycling rate over the Main Ring there is a major increase in the
number of proton-antiproton collisions that can be created and observed in the Tevatron.
This extends the physics "reach" to higher mass and rarer particles that may, if
discovered, expand our understanding of the nature of matter and the forces that hold it
together.
The Main Injector will operate
simultaneously in fixed target and antiproton production modes. A very intense 120-GeV
beam can be extracted. Targeting this beam will create an intense beam of neutrinos. This
beam will used to study the basic question: do neutrinos have mass? This is the NuMI project, Neutrinos at the Main Injector.
The Recycler
This is the 8th largest synchrotron
in the world and is built from "refrigerator" magnets.
The Recycler is a fixed-energy
storage ring placed in the Main Injector tunnel directly above the Main Injector beamline,
near the ceiling. The purpose of the Recycler is to further increase the luminosity
of the Tevatron Collider over the luminosity goals of the Main Injector by itself.
Using permanent magnets removes the
need for expensive conventional iron/copper magnets along with their power supplies,
cooling water system, and electrical safety systems.
The Recycler is just a ring of
"rainforest-green" steel cases holding bricks of magnetized strontium ferrite
(the same material used in refrigerator magnets) mounted on steel hangars.
The Recycler will be a high
reliability storage ring for antiprotons. Because there are few power sensitive
components, there are virtually no mechanisms for inadvertent beam loss.
The Recycler will function as a
post-Accumulator ring. As the stack size in the Accumulator ring increases, there comes a
point when the stacking rate starts to decrease. By emptying the contents of the
Accumulator into the Recycler periodically, the Accumulator is always operating in its
optimum antiproton intensity regime.
The third role of the Recycler, and
by far the leading factor in luminosity increase, is to act as a receptacle for
antiprotons left over at the end of Tevatron stores.
What is the
difference between Colliding Beams and Fixed Target?
Circular machines, the
Lorentz force and how synchrotrons work
Link to the Main Injector Department
