Thursday, September 29, 2016, 10:00am EDT - Compton

From Hall A Wiki
Revision as of 22:07, 28 September 2016 by Cornejo (Talk | contribs) (Photon Detector)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
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=F228 in Cebaf Center


  • Ole is getting serious about turning off compton-old
    • I've copied some stuff to /home/compton/compton_old on the new machine
    • Check and see if there's anything I've missed that you think is important (Alexandre...)
    • VNC and StripTool now working
  • Simulation: unified GEANT4-based Monte Carlo update
  • Alignment was done last week. Laser table was several mm low --> likely due to replacement of laser table leg valve.


  • Removed 5 W fiber amplifier and handed off to Shukui (Injector group) - he says it's working "fine," but hasn't looked at it with fast photo diode
  • Installed 30 W amp
    • Polarization direction found
    • Producing 1-1.1 W at nominal 5 W out of fiber amp (similar to what we were getting before when things were working well).
    • Not yet able to lock - tried to reproduce configuration and settings from previous running; no luck. Perhaps PZT response different for this seed laser?

Photon Detector

  • Detector installation and DAQ (Update from Juan Carlos and Abel)
    • PbWO4 and Tungsten Collimator system on table
    • Collimator system controller reachable from network (need to ask network people to provide DNS records)
    • Checked limits of table motion
      • Maximum height (y-position) now ~29 mm (this is down from 39 mm during Spring running). At 30mm foam touches top plate.
        • However, we presently cannot reach ideal height due to interference of PMT connectors and a bolt from top plate. Will attempt to rotate or adjust detector to clear it.
      • Will need to find an elbow HV connector to prevent accidentally bumping HV cable on the back of the table.
    • Aluminum collimator left open (1cm radius) and removed old sync shield.
      • Still have enough room to insert the smaller Al-collimator if needed.
    • Camera temporarily "taped" to top plate. Want to get a clamp to better secure it.
    • Integrating mode DAQ brought back to life (finally).
      • Had issues with some missing signals/cables but managed to track them all down.
      • PMT triggers (for snapshots, etc..) works, but Pulser triggered (min-Megan) still needs work.
      • Once Spring DAQ up and running like normal, will test new CRL file for fall running.

Electron detector

  • Detector in Hall
    • FSD and "photon stopper" valve: need to test masking
    • Measured noise still ~ 20 mV. Too large
  • QWAD tests: JLab (Hoskins/Camsonne)
  • QWAD tests: Manitoba