General Meeting Summary 3/26/20

MAGNET (Charles)

• Work on To-Do List items, e.g. checking measurement vs. 3D model is ongoing - see NPS To-Do List for a complete listing

MECHANICAL DESIGN (Bogdan, Steven L.)

• Check and document all kinematics with latest requirements for interferences, e.g. shelf plates on SHMS and new experiment DVCS from Hall A

• Action Item: collect and send the kinematics information to Steven L. (DVCS: Carlos/Charles, WACS/CPS: Bogdan/David H.)

• Document time estimate for rotating the magnet, moving the NPS detector and cabling, moving NPS from one side to the other

• Action Item: develop possible models for cable layout - might need to get in touch with Brad and Jack

• Corrector magnet fit - Bogdan will work with Paulo on the details

FRAME (Carlos)

• Magnetic shield tests - note: max field expected is ~200 Gauss longitudinal

• measurements show that 0.5mm mu-metal works in that range of magnetic fields
• initial measurements show that PMT signal in magnetic field drops faster than projected by the manufacturer - discussion about possible residual fields, which could cause this effect, also could lead to a transverse field.

• Action item: try to degauss the mu-metal - can be done with Helmholtz coil (see the FCAL-II magnetic field shielding)
• Another option: anneal the mu-metal

• Assembly of the frame started and was well underway until the lab shutdown on March 16 - anticipated delay roughly equal to length of closure

• Crystals and LED connectors sent from JLab arrived in France - should be delivered at Orsay end of the week

CRYSTALS (Vladimir, Tanja)

• Crytur has been sending more crystals (50+10) over the last weeks - production seems to continue

• Action Item: Check with CRYTUR if they can expedite outstanding crystal delivery for 250 crystals purchased recently and possible early FY21 procurement for 200 more

• SICCAS shipped a number of crystals - arrival at JLab not yet known

HV DIVIDERS (Fernando, Alex S.)

• New HV dividers with additional amplification that improves linearity have been tested in Hall D and seem to perform well

• Action Items:

• Collect results from Hall D and projected intensity of signals and performance for Hall A/C conditions
• Collect all information on Hall A/C projections, e.g. from Ho-San's simulations for discussion at next meeting

DISCUSSION (All)

• NPS global delay likely a few months - will evaluate when Labs/Universities return to normal operations

NEXT MEETING: THURSDAY 16 APRIL AT 9:00AM (ET)