Wednesday, March 18, 2020, 2:00 pm EDT

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Back to Main Compton Page >> Compton Meetings

1. Dial Toll-Free Number: 1-888-240-2560 (U.S. & Canada)
2. International participants dial:
Toll Number: 1-408-740-7256
3. Enter meeting ID:140287970

Desktop sharing: 


Meeting room = None. Remote only.


  • Keep taking data!

Electron detector

  • QWAD preparation progress
  • Analysis updates


  • Laser polarization systematic tests: Preliminary results from HWP=73 and 56 deg. [1], [2]
  • Other options for "reasonable" values of RRPD: [3]

Photon Detector

  • Compton edge decreasing [4]
  • Steering vs. spectrum [5]
  • Spectrum fitting for collimator offset: Target dependence? Drifting gain + low amplitude backgrounds?
  • LED run


  • Online analysis results
  • Polarization vs. time


Mark D, Dave G, Adam Z, Kent P, Brian Q, JCC, Cip G, Amali P

  1. Photon Detector
    • Table scan: Epics logger stopped writing to the CODA file so the scan is very difficult to recover. Should be redone after procedures are made more robust.
    • Planned systematic study of angles of the electron beam will be done ASAP after the Moller today.
    • Possible new additional background from calcium that was not observed earlier. Amali investigating.
    • Tube gain is decreasing but still completely functional. Increasing the voltage to recover the gain might affect the linearity.
    • Pulser trigger doesn't work when there is beam. Need someone to verify the trigger logic in the hall. Opportunistic access.
  2. Laser
    • Systematic checks wen't well. Other systematic tests are the "second solution" of the same sign or to change the sign. elog 575
  3. Electron Detector
    • QWADs in EEL126 for channel adjustment.
    • Possible access to reinstate old system.