General Meeting Summary 4/26/18

TIMELIKE COMPTON SCATTERING

• Update on projection studies

• Discussion about TCS setup

• Discussion about proton identification (along with electron and positron) - current idea is to use tracker for time-of-flight in addition to energy deposition

• Can one identify protons also with hodoscope and shower counter alone?

• Discussion about backgrounds and trigger

• Background rates seem difficult to manage, puzzling: e-/e+ at large angles (pair production at high momentum?) - possible option: design trigger to make manageable
• Need to understand where particles of interest go

• Plan for proposal: submit to PAC46

• Action Items: Show what setup will work including showing need for tracker

NPS FRAME

• Work progressing well and faster than before as more resources available now

• Overall Plan: final design at end of year, construction in 2019, ship to JLab in summer 2019

• Near-term plan: build prototype to test mechanical aspects: stability of system, assembly - expect first results end of May 2018

• Also plan to travel to JLab end of summer for discussion of details with designers

• Current focus areas: Cooling system, dealing with cables, connector budget

PMT/HV BASES

• Making good progress. Connectors were on back-order, but should arrive end of week - work can start then

• No physical final design yet, but Julie has photographs of new board/connectors

• New board and connectors feature 5 pins on board and connectors have both signal and HV

MAGNET

• Work started in test lab with mechanical assembly. Photographs show:

• Front clamp
• Part of yoke
• Gap - nonuniform shape of magnet

• Water and power are being setup in test lab for magnet testing

CRYSTALS AND PROTOTYPE

• Crystal tests ongoing (SICCAS, systematic uncertainties between setups)

• Prototype (3x3) calibration procedure

• Results show energy resolution of 2.2% - this method uses all data from run, no scan of detector segments as previous method
• Next steps to improve resolution: PMT gains and HV optimization, more statistics, timing adjustment, central pair spectrometer tile search improvement

NEXT MEETING: THURSDAY 10 MAY at 9:00 AM (EDT)