Meeting 17 April 2020

DISCUSSION TOPICS AND MATERIAL

• Radiation Simulations

• Update on simulations
• Analysis of results from February/March 2020

• CPS Layouts in Hall C (Steve L., Mike F.)

• Hall D CPS configurations (Sean)

• TCS low momentum proton studies (Vardan)

• Other

PARTICIPANTS: Vladimir Berdnikov, Marie Boer, Josh Crafts, Sean Dobbs, Rolf Ent, Mike Fowler, David Hamilton, Tanja Horn, Dustin Keller, Thia Keppel, Steven Lassiter, Paulo Medeiros, Hamlet Mkrtchyan, Gabriel Niculescu, Igor Strakovsky, Vardan Tadevosyan, Bogdan Wojsekhowski, Dan(?)

RADIATION SIMULATION UPDATE (Gabriel)

• General idea: reduce tungsten - activation goes up - get back down by adding lead

• with trading tungsten in center for lead layer --> Activation >1mrem/hr, seems to work well
• can see that that with 10cm lead can eliminate a jump in activation
• Prompt - not crazy, but needs more thought, shielding around target area?

• Action item: reduce prompt radiation

• Add plastic layers in the forward region (Page 4 in analysis pages) - how much green is needed? Mitigate radiation from target
• Analyze exit channel contribution, e.g. close front entrance channel completely, maybe can optimize steps of opening

CPS LAYOUT IN HALL C (Steven L., Mike F, Paulo)

• Two general notes

• no CPS disassembly after experiments due to high activation level
• CPS needs space in hall and some way to move it - cannot use a mobile crane
• CPS experiments would be separate from NPS only experiments - in this configuration cannot use HMS/SHMS and would have to use BigBite or NPS as detectors, lose pointing at target

• Investigations of difference scenarios - all have pros and cons to be evaluated

• Investigation CPS upstream of pivot - much interference with Hall C infrastructure
• Investigation CPS downstream of pivot - overall less impact on existing equipment in hall, but need new pivot design, cryo lines

• Action items:

• need feedback from physics about upstream and downstream

• • could replacing W with Pb apply to Hall C downstream of pivot option?

• In principle yes, but need to minimize the distance from CPS to target. Will have to check.

HALL D CPS CONFIGURATIONS (Sean)

• Presentation of different configurations

• Magnet sizes: 45cm x 2cm, 60cm x 1.5cm, 90cm x 1cm
• Default shielding: same as Hall A/C CPS plus 20cm up and downstream shielding

• Main point is the magnet size: deposit power in long length of copper, temperature in copper has to be controlled, might have to be larger to deposit more power

• Shielding weight not so much a problem - if assume 100 tons for Hall A/C then probably same, additional weight comes from larger magnet

• Action items:

• Make sketch of CPS Hall D and estimate weight - Sean thinks good to start with 45cm and 90cm options
• Maybe can do all shielding with lead? Evaluate if W really needed.
• Make calculation of radiation like Hall A/C - maybe simplified version to start with

CPS LEAD SHIELDING MATERIAL (Bogdan)

• Radcon JLab guidance:

• Need radiation assessment from SLAC
• Need to use designated vendor

• Action items:

• Waiting for SLAC to resume operations
• Arrangements for shipment and receiving

TCS SIMULATION - LOW MOMENTUM PROTONS (Vardan)

• Can now see the tracks of 400 MeV protons, escape target and scattering chamber

• Hit pattern at layer 1 correlated vertical track deflection at vertex

• Noticeable effect from particle interaction with matter

• Action items: further optimize tracker

• Could start with a single, very large detector and then optimize for capturing science
• Could use SBS chambers (much bigger), then optimize with making dead material in between.

• Or perhaps GEMS from PRAD?

• Configuration optimization: make strip configs different: x-y and u-v etc., multiple trackers in different directions

NEXT MEETING: 8 May at 11AM (ET)