General Meeting Summary 4/26/17

DETECTORS AT JLAB (Vardan for Arthur)

• Discussion about SHMS aerogel Cherenkov detector tray SP-11 (aerogel of refractive index n=1.011)

• guard wires have been installed - see this picture of the SP-11 tray with wires and another picture of the fully assembled tray with markings on top of the SP-20 tray
• Next steps: schedule tray installation into SHMS with Walter's group, install the tray, take cosmic data

• HMS aerogel cherenkov detector located in room above Walter's machine shop awaiting further testing, e.g. PMTs

• NPS HV dividers discussion

• new active design performs according to specifications up to 1-2 MHz
• no substantial impact of cable length on signal
• Next: decide in 4 May NPS meeting about final geometry (circular vs rectangular)

TIMELIKE COMPTON SCATTERING UPDATE (Vardan)

• Results from recent detector simulations with Geant4 are consistent with previously used simple Fast MC - observed 10% difference in rates might be due to the models

DETECTORS AT CERN (Rachel)

• CMS closed and magnet being ramped up to field (anticipate ~10 hrs to 3.8 T)
• Pixel detectors are off until magnet at field and stable beams have been established. However, some cosmic data taking for diagnostics may be possible during beam commissioning

PBWO4 STUDIES AT CUA (Richard, Andres)

• Mechanical part of crystal prototype nearly finished, calibrations ongoing

• Photodiode based readout of PbWO4: ongoing tests in noise-controlled environment.

DATA ANALYSES (Salina)

• Deeply Virtual Compton Scattering experiment data analysis focus is currently on calibrations of data taken over the last year

• Deadtime calibrations ongoing - need to be finalized
• Calorimeter algorithms for cluster identifications and pi0 identification
• Acceptance function and radiative corrections

NEXT MEETING: WED. 3 MAY AT 10:00 AM (EDT)