General Meeting Summary 8/23/18

MAGNET (Bogdan)

• Anticipate continuation of assembly after Hall C closed

• Magnet mapping report at next meeting (Charles)

• Action Item: Check on finalizing of design (vacuum connection etc.) - Bogdan will talk to Mike Fowler

NPS PROTOTYPE (Vladimir)

• Modules have been assembled with help from Hakob, tests are ongoing

• Platform is not yet ready

• Projected timeline is to move prototype into Hall D in middle of October, then connect, power up, etc.

• Action Item: Discuss specific tests to do with prototype aside from the nominal tests - examples could be energy resolution at different energies of temperature, but need expert input on what is possible

CRYSTALS (Vladimir)

• Preparations for shipping back bad crystals to SICCAS ongoing with help from Hakob - plan is to ship at least one crate in first week of September, one crate holds 8 boxes (10 crystals per box)

• Most of the bad crystals fail visual inspection or transmittance @420nm and were not further tested for light yield or radiation hardness

• In contact with CRYTUR about 100 crystals - production seems to be ongoing

FRAME CONSTRUCTION (Carlos)

• Assembly of 3x3 prototype is ongoing - expect to have all components by end of month (already received 9 HV bases from Julie, 9 PMTS are being shipped from JLab)

• Testing curing system with blue and IR LEDs -procedure: irradiate crystals at 30 Gy, then expose to blue or IR LED. Demonstrated that blue light can recover crystals, IR is less efficient. Also found that if irradiate at very high doses (1000 Gy), no recovery by light can be done - requires thermal annealing. Trying to look for threshold - based on literature, threshold might be 50kRad

SIMULATION (Ho San, Carlos)

• Implemented magnetic field into NPS detector simulation, but some questions - more detailed report at one of upcoming meetings

PRESENTATION ON nDVCS (Eric Fuchey)

• Some of the comments:

• Check mTPC effiency on -t (since this is the quantity that's ultimately the one of interest)
• Check carefully if really need SiPM - might want to consider shielding magnet first
• NPS detects high energy photons, otherwise mainly need an electron detector - might want to check if really need the full SBS setup

NEXT MEETING: THUR 6 SEPTEMBER AT 9:00AM (EDT)