General Meeting Summary 8/24/17

MAGNET UPDATES

• Yoke delayed until end of September

• Main coil delayed until end of November

• company miscalculated amount of copper needed and takes a few months to obtain
• in general, company does good work

• Test lab configuration for magnet assembly and testing ongoing

• due to delays of magnet component shipping magnet tests will be delayed past December

CRYSTALS AND PMTS

• Received 100 PMTs from Hamamatsu

• diameter < 19.2 mm according to specifications

• Crystal shipment delayed

• Check with company at beginning of September for expected delivery dates

• Crystal Q&A documentation discussion

• need to make sure that there is unique labeling and data sheet for each crystal
• create an NPS database that includes crystal info, but also info on PMTs, frame etc.
• indicate what tests have been done by Giessen and/or CMS - use this information to determine if crystal good with respect to these two
• Discussion about resource optimization

• split measurements between institutions
• measure only subsets
• external resources to supplement resources at CUA/IPNO - Glasgow may be able to help with some tests

• Discussion about crystal measurement procedures

• make a detailed list of procedures to follow to minimize damage to crystals

FRAME UPDATES

• Designer will be available full time at IPNO in September

• Currently working on curing system optimization and finalization

• Still need some final design optimizations from JLab designer, e.g. interference in detector box

DISCUSSION ABOUT 2017 ACTION ITEM LIST

• Magnet mapping - discussions and write-up of plan ongoing

• plan to map along beam line for 2-3 positions
• primary tools: hall probe and oscilloscope
• may be able to do some tests with yoke and corrector coil before main coil arrives

• Platform - JLab designer

• DAQ and Readout

• Discussion about data rate

• DVCS experience showed 20 MB/sec was fine, but 40 MB challenging (read every 1 ns)
• HC network currently goes to 1 GB/sec, but anticipate that rates will be challenging without dedicated network upgrades, additional storage tapes would also be required

• Action item: check if really need to read full waveform

• in general, need full waveform because of pile-up
• could develop NPS simulation or use existing Hall A data (note that crystals are different) for rates and see if pile-up is an issue
• could perhaps test readout for background contribution with prototype (fully cabled, one crate) with beam in Hall C, absence of magnet should not be an issue since can always put crystals at larger angles

• Discussion about goal of prototype

• full chain test with HV cables - determines suitable lengths etc.
• determine if need to read with full wave form or trigger

• Crystals - large part of planning work completed, some still ongoing, waiting for crystals

• PMT and HV bases - concept finalized, procurement ongoing

NEXT MEETING: THURSDAY 14 SEPTEMBER AT 9:00 AM (EDT)