Meeting 31 October 2017
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PRESENTATIONS
- Additional files sent after the meeting: Prompt Dose Rate 2D and 1D-Z
6-point list and Geant4 model (Bogdan)
NOTES
SIMULATIONS
- Discussion of Jixie's results based on Bogdan's model - note that at the time of the meeting prompt radiation results were not yet available and that target had not yet been implemented
- Next steps for simulation studies
- Prompt radiation - quantify damage (in mrem) with and without source
- Need to know what the extra contribution from CPS is compared to target alone - if source contributes 10%, then could consider CPS optimized
- Next step: optimization of shielding - can we make it thinner?
- Specify radiation at pivot where detector (closest approach is 2 meters from the pivot) and materials are
- Required filling out space with appropriate materials
- Run flux of photons through target and see what get for pure photon source
- Implement polarized target magnet
6-POINT LIST FOR PREPARING CPS TECHNICAL NOTE (p. 1-21)
- Discussion of the list:
- Raster is 2mm x 2mm (requires polarized target rotation)
- Magnet pole is shaped to boost the B field to 3.2 T - length reduction, which leads to a better front shield and wedged absorber
- Central absorber of Cua has 1.9x better heat conductivity, 4.2x longer radiation length than the W-Cu(20%) alloy
- W-powder external shield (16g/cm^3 density) for better shielding
- Gradually "stepped" opening of the beam line for radiation leak reduction
- Shielding requirement logic: the radiation from the source should be a few times lower than from the photon beam interaction with the material of a polarized target
- a very rough projection of radiation in the hall due to photon beam and target interaction based on RCS data from 2002 is presented - caveat is that the experimental conditions may not be the ideal comparison for the simulation, but may give ballpark guidance
GEANT4 MODEL (GEMC FRAMEWORK) SIMULATION (p. 22ff)
- yellow volume on page 24: TOSCA model, rectangle, then eliminate all magnetic material
- most trajectories of 11 GeV electrons are confined to volume - visually looks ok
- working on heat deposition
COLLABORATION MEETING
- The preliminary agenda is presented, fits generally after the Hall C meeting on Tuesday, waiting for Thia for confirmation if NPS meeting can start at 3pm
NEXT MEETING: TUESDAY, 22 NOVEMBER 2017 AT 3:00PM (EST)