Compton Meeting, February 14, 2011

Attendance

Kent, Amrendra, Mark, Vladas, Wouter (minutes), Dave (chair)

Minutes

• Only last few days we had good beam
  • before that, bad background, flucts in norm scint by factors
  • since Friday/Saturday we have better conditions, S/N of 50%

• CPslow keeps locking up
  • memory issue? need to run memtest on it at next access
  • pictures of every lock-up would be useful
  • hcreboot switch from GEM will be used for Compton
  • Don set it up to reboot on exception error, not tested yet

• Electron detector
  • presentation by Vladas
    • efficiency of ~8% for plane 1, ~2.5% for planes 2 and 3
    • efficiency-corrected population per strip looks reasonable
    • Compton-edge at strip 48, or 1.74 cm (according to Mark & Jay's calculation)
    • strip 0 is approximately half-way between rho = 0 and rho = 1
    • now 3.6 mm away from beam?? should be 8.5 mm to strip 0, so maybe 7 mm, but then guard strips, and first 4 strips are connected to ground... so maybe 6 mm