GlueX TOF Meeting, September 25, 2019

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GlueX Time-of-Flight Meeting
Wednesday, Septemer 25, 2019
10:00 am
JLab: CEBAF Center, Room F226
BlueJeans: 350 531 998


  1. Announcements
  2. Review of minutes from the last meeting
  3. Upgrade Status Media:TOF_pmt.jpg Media:TOFII.jpg
  4. Software Issues
  5. GlueX and TOF NIM papers (Beni)
  6. Action Item Recap


Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2019 on the JLab CUE. This directory is accessible from the web at .



  • FSU: Jason Barlow, Edmundo Barriga, Paul Eugenio
  • JLab: Mark Ito (chair), Simon Taylor, Tim Whitlatch, Beni Zihlmann

There is a recording of this meeting on the BlueJeans site. Use your JLab credentials to access it.

Review of minutes from the last meeting

We reviewed the minutes of the meeting on August 28. We have to remember to add the CAEN TDC non-linearity calibration to the run plan for November.

Upgrade Status

  • Tim showed a photo (shown below) of a single PMT on the TOF which is out of alignment. Paul was not too concerned. Tim can shim things up so that the steel magnetic shield will fit. Beni will take a look at the tube with the scope to make sure it looks good from that point of view.
    TOF pmt.jpg
  • Paul asked how much torque was applied to the bolts holding the steel frame against the scintillator counters. Tim discussed this with the crew before performing the operation; they tightened the bolts until the between the frame and counters was compressed by 20%.
  • Tim reported that Survey and Alignment will be fiducializing the TOF today. The x-y position will be shot off the frame of the beamline hole. Roll, pitch, and yaw will be determined from points on the outer edge of the steel frame.
    • Mark mentioned it would be nice to have some kind of measurement of the increase in the width of the array beyond the sum of the theoretical scintillator width due to wrapping and geometric imperfections. Tim assured him this will come as a by-product of the survey.
  • We should add cable labels to the frame as was done for TOF I near the end of its life.
  • TOF will be mounted on the forward carriage on or about a week from Monday.
  • Once the array is mounted, Paul will turn to the design of the Lucite shield.

NIM Paper

Beni reports that the calibration section of the paper is nearly done. The main lack at this point the construction section. Paul will turn to that once TOF II installation settles down.

We will come up with a backup scheme for the Overleaf site.