GlueX Start Counter Meeting, January 26, 2017

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GlueX Start Counter Meeting
Thursday, January 26, 2017
11:00 am EST
CEBAF Center, Room F326/327


  1. Announcements
  2. Review minutes from the last meeting
  3. Run Readiness
  4. Calibration
    • Issues with propagation delay calibration?
  5. NIM/TDR
  6. Action Item Review




Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2017 on the JLab CUE. This directory is accessible from the web at .



  • FIU: Werner Boeglin, Mahmoud Kamel
  • JLab: Mark Ito (chair), Simon Taylor


The Hall will close on Friday. Beam is expected on Monday.

Review minutes from the last meeting

We looked at minutes from January without significant comment.

Run Readiness

Mark completed Hot Checkout. There was a problem analyzing data due to missing information for the number of samples summed to get a pedestal value. We think this is due to using the stand-alone DAC (TI) rather than the global system (TS). The code was kludged to make this work, but a more permanent solution should be on its way.

Calibration, Propagation Delay

  • Mahmoud reports getting non-physical values for the speed of light in the scintillator.
  • Sean has been looking at the calibrations as well. With the previously poor TOF calibrations, he was seeing time shifts in a few paddles, presumably from picking the wrong RF bucket (500 MHz). He is now re-running the calibrations with recently improved time constants for the TOF from Beni.
  • Sean asked that Mahmoud check, for the channels that are not showing problems, whether the constants are consistent with those found in the Spring. We do not expect propagation delay to change from run to run.
  • Werner talked to Eric Pooser about the Start Counter NIM paper. Eric is busy with the KPP run in Hall C at the moment; when that is over he will have more time.

Collaboration Meeting

Mahmoud will give an update on the calibration at the meeting next month.