General Meeting Summary 7/19/18

SWEEPING MAGNET (Charles, Bogdan)

• Magnet assembly ongoing in test lab

• Magnet mapping setup has been designed - need to check with Walt about fit into test lab infrastructure

• Measurement will be at multiple positions inside magnet gap
• Device has a 80 inch travel path longitudinal and also moves up and down, uses a stepper motor - could in principle do continuous measurements
• Note: in test lab will only measure at small fraction of total magnet power (~10%), will not saturate the iron - need some sort of hysteresis curve

• Action Item: Magnet mapping procedure test plan specifying:

• What currents
• What step sizes
• How many measurements
• What precision
• What hall probe - might not have one for all three axes

CRYSTAL PROTOTYPE (Vladimir, Alex)

• Mass production of crystal-PMT-HV-divider assembly has started

• Prototype bigger than originally planned - need to characterize additional 60 crystals from SICCAS 2017 shipment

CRYSTALS (Vladimir, Tanja, Carlos)

• Preparations for shipping bad crystals back to China ongoing

• Procurement of crystals from CRYTUR and SICCAS ongoing - final numbers depend on pricing

• Discussion about plans for next FY

• SICCAS meeting with company at their facility in Shanghai on 23 July (8:30am-noon China time)

• Discussions will include presentations on NPS/EIC projects (Carlos), FCAL-II and Comcal (Liping) and by the company

HV BASES (Rolf for Julie)

• Some bases were brought to JLab - connectors are very large, but can deal with it

FRAME (Carlos)

• Building 3x3 prototype to test mechanical assembly - goal is to test how easy and practical it is to assemble crystals and to replace a PMT, e.g. the one in the middle

• difference to HyCal: use screws on the back to push PMT against crystal, no glue at contact, optical grease will be used

• discussion about compensating the force - in RCS used a back support structure
• discussion about dead zones between crystals - for each crystal have support in front and back - held together globally by the box, carbon frame only at front and back to reduce material (dead zones) between crystals

• Action item: include front plate in simulation to check possible effect on resolution

NEXT MEETING: THURSDAY 23 AUGUST at 9:00 AM (EDT)