Wednesday, July 12, 2017

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Meeting Information

  • Location CC L210A, 11 am
  • DocDB

Blue Jeans Connection Information

  1. Enter Meeting ID: 895800575
  2. Press #


  1. Commissioning plan updates from detector systems
  2. Status update from detector owners, calibrations, efficiencies, etc.
    1. Shower HV Calibration
    2. Noble gas Cherenkov Update
    3. SHMS DC3 Repair Update
  3. Review systems owners and update information
  4. Address system specific points of interest for the Fall 2017 run



  • SHMS magnet cycling procedure: Dave M. did hysteresis cycle on Q2 by going to 2/3 Vmax
  • They were able to fit zero offsets and replicated the effect which Dave G. had observed which was that there is remnant current that resides in the magnet after ramping to zero
  • Moving forward they want to cycle to VMax and then turn on Q1 and Q3 to investigate cross talk
  • Issues with the ESR have delayed some things
  • Ground work for FADC scaler integration has been conducted
    • More work with Brad to integrate it into the DAQ is planned to occur soon

Beam Line

  • BCM checkout: Dipak was given a current source by Dave M.
    • He will work on it when he gets back from MU


  • Work to configure the triggers for the upcoming experiments will commence within the next couple of days
  • Electronic dead time: 100 Hz pulse generator is being utilized to fire the SHMS hodoscope planes (and sides)
    • A discriminator copy is fed into a TDC channel
    • The setup is complete, a few runs have been taken at various frequencies
    • The HV for the PMTs have been turned off for sanity checks
    • The expected behavior has been observed
    • More detailed studies/plots to come



  • Latif performed more latency scans however they encountered issues with high voltage
    • The issues were that the HV would only hold current for a couple of days before crashing
    • The cause is not clear
    • To monitor the HV they setup a remote HV setup so they can control the HV and monitor it
    • They have the capability of monitoring the current draw etc.
    • The observed history indicated that the current was stable
      • It was thought at one point that the current was tripping however this was not the case
    • Yesterday they sent the power supply to the electronics shop for assessment and repair
  • Work is ongoing regarding the analyzer
  • The plan is to setup a single serial channel to control the HV
  • It does not need to be read out via EPICS
  • All GEM operations will be expert driven during the run period

Nobel Gas Cherenkov

  • Ryan showed some slides regarding the NGC analysis for run 488
  • The pulse integral spectra are not understood
  • Many suggestions regarding the analysis were suggested however the take home message is that Ryan should begin with fiducial cuts on the respective mirrors etc.

Drift Chambers

  • Deb showed some slides regarding the repair of DC3
  • Previously there we many missing wires, ringing on a few channels, and suspected gas leaks
  • The issues from missing wires were a result of bad soldering
    • They were re-soldered and checked for functionality
  • They found a small burn possibly from discharge on the cathode plane
  • A broken wire was found (it was broken under the epoxy) and the wire was re-strung
  • It was found that the tape from the gas window was overlapping the O-ring
    • It could likely be the cause of the observed gas leak
  • Plans moving forward are to condition the chamber and check hit maps etc.


  • Simona reported the PMTs for the quartz plane should arrive beginning of August
  • They are working on the box assembly for coupling PMTs to the quartz bars
  • They are working on fabricating optical cookies
  • Carl Zorn is working on a QE measurement for the new PMT's


  • Vardan showed showed his logbook entry in which he was working on developing a procedure for gain matching
    • During KPP we had a run at 1.4 kV and a run for 1.5 kV
    • The analysis selected the MIPs to locate the peak positions and compare the 1.4 kV run to the 1.5 kV run in order to measure the peak location difference difference and thus measure the voltage dependence of the signal location
    • He selected pion events via cuts on the Chernkovs
    • He selected MIPs via the pre-shower to ensure the pions did not shower in the pre-shower
    • He selected events in which a single calorimeter block had fired]
  • In summary the expected behavior for an 8 stage PMT was observed
  • it was discussed that the some of the voltages that were gain matched is higher than the Hamlet limit of 1500 V
  • Dave M. Suggested that we can change the trip set point in the CAEN mainframes to 0.1 s down from 1.0 s in order to be safe