General Meeting Summary 8/2/17

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SHMS AEROGEL DETECTOR (Arthur, Andres, Marco,...)

  • Aerogel tray exchange from SP-11 to SP-30 planned for next few days
  • Discussion about events detected from outside the active area for SP-11 aerogel tray
  • Cosmic data suggest that these are scintillation events
  • for comparison, data from full trays show background (not from aerogel) on order 1 photoelectron
  • Action Item: estimate impact of few photoelectron background on particle identification (proton rejection)


HMS AEROGEL DETECTOR (Arthur, Richard, Salim)

  • CUA received 3 Burle 8854 PMTs from former SOS aerogel cherenkov detector (aerogel was n=1.05) - 5 more PMTs and the detector box are at JLab
  • These PMTs are about 20 years old
  • HV range up to 2500 V, tests at 2200 V show good signals on scope without noise (Pic1, Pic2, Pic3, Pic4, Pic5, Pic6, Pic7, Pic8)
  • Action Item: Need to check single photoelectron and quantum efficiency for these PMTs
  • Initial checks in darkbox promising - full tests ongoing
  • PMTs show small after-pulses - can be considered noise. Question: what was the helium source at MIT/Bates?


DIRC (Greg)

  • Discussion about optimizations of the monitoring system for transporting SLAC DIRC bars to JLab
  • prototype built at Indiana
  • expect transport to happen this fall
  • Discussion about sensor tests and lens prototype tests at CERN


PION AND KAON STRUCTURE FUNCTION(Dannie)

  • Completed kinematic studies for kaons, working on pions next
  • Working on offshellness correction
  • Next will start looking at detector simulation to include resolutions


IMPACT OF REFLECTOR ON CRYSTAL LIGHT YIELD (Casey)

  • Tested different materials, difference combinations, and different thicknesses
  • Teflon performs best, mylar not very good
  • Next will test additional materials including Gore reflector (that was used in SHMS aerogel Cherenkov detector construction)
  • Discussion about cutting reflector to shape rather than trying to wrap