Subject: Minutes - Linac Momentum dump Meeting - 11/9/2010
From: Fernanda Gallinucci Garcia
Date: Tue, 09 Nov 2010 15:00:17 -0600
To: Diane Reitzner , Ang Lee , Rob Reilly , Ben Ogert , Duane Newhart , Patrick Karns , Larry Allen , Joel Fulgham , Gary Lautenschlager , Fernanda Gallinucci Garcia , kamran Vaziri

Attendants: B. Ogert, A. Lee, D. Reitzner, K. Vaziri, J. Fulgham, R. Reilly, D. Newhart, F.G. Garcia
Location: Bungalow
Date/Hr: 11/09/2010 1:00pm
1) Lee's Heat and Stress Calculations
2) Empirical experience with graphite under vacuum


Meeting started with Lee's presenting heating/stress calculations for
a) Copper (Cu) & SS sleeve
b) Graphite (C) & SS sleeve
c) Tungsten (W) block
d) Graphite core & Tungsten sleeve

His whole presentation can be seen here (
The calculations show that either W block and C core + W sleeve should work for both scenarios: Operational + Accidental.
The W block seems to be the simplest  configuration  and the recommended  length is 24 cm.
However, the W + C core has the lowest temperature rise due to C core.

Kamran pointed out the possibility of having a higher residual dose rate in the enclosure due to W usage. W has the potential to create longer live isotopes than graphite.
On the other hand, graphite presents problem with oxidation, for instance. Kamran recommended that if this option is chosen, that the sleeve be made with a container surrounding the graphite. During the manufacture process, the graphite should be packed while purging inert gas, such as argon, to significantly reduce the Oxygen content. This raised another concern, when Rob Reilly pointed out that if the graphite in inserted in this container, the rise in temperature by beam hitting the core would increase the pressure inside this volume.

Next Steps:
1) Rob Reilly will investigate the mechanical aspect of using W. Explore the options in creating a flange with SS & W transition in order to explore the W block option.
Depending on how successful this process it, he will inform Diane who will run MARS with this configuration and present the residual dose, stars distribution with beam and W.

Next meeting: 11/30/2010, 1:00 pm. Bungalow.

PS. Please send any correction for this minutes to me.

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