Difference between revisions of "Meeting 31 October 2017"
Jump to navigation
Jump to search
| (4 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
| − | PRESENTATIONS | + | '''PRESENTATIONS''' |
[https://wiki.jlab.org/cuawiki/images/1/11/Jixie_CPS_Oct31-2017.pdf Simulation Update (Jixie)] | [https://wiki.jlab.org/cuawiki/images/1/11/Jixie_CPS_Oct31-2017.pdf Simulation Update (Jixie)] | ||
| Line 7: | Line 7: | ||
| − | NOTES | + | '''NOTES''' |
SIMULATIONS | SIMULATIONS | ||
| Line 14: | Line 14: | ||
* Next steps for simulation studies | * 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 | ::::* 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? | ::::* Next step: optimization of shielding - can we make it thinner? | ||
| Line 26: | Line 26: | ||
* Discussion of the list: | * 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 | ::::* 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 | ||
| Line 47: | Line 47: | ||
| − | NEXT MEETING: TUESDAY, 22 NOVEMBER 2017 AT 3:00PM (EST) | + | '''NEXT MEETING: TUESDAY, 22 NOVEMBER 2017 AT 3:00PM (EST)''' |
Latest revision as of 09:47, 22 November 2017
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)