GlueX TOF Meeting, October 9, 2019

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GlueX Time-of-Flight Meeting
Wednesday, October 9, 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 ASSY.jpg
  4. Software Issues
  5. TOF NIM papers
  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: Edmundo Barriga, Ashley Ernst, Sasha Ostrovidov
  • 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 September 25.

  • Beni has looked at the channel with the drooping PMT that was pointed out last time and it looks good on the scope. Tim agrees with Paul that the glue joint is intact on that end of the counter. See Tim's photo and see if you can find the PMT in question.
  • Tim will ask the guys to put new labels on the frames to indicate which cables go where.

Upgrade Status

We looked at Tim's recent HDList entry.

  • The support frames will be put on today.
  • The array will be mounted on the forward carriage tomorrow.
  • Survey will be done on Friday.
  • The TOF will be aligned with the FCAL. It is known that the FCAL is 6 mm off from beam center, but there is no plan to move it. If such a plan develops, the TOF will move with it.

Software Issues

TOF Component and Cabling Tables

Mark has put together a database that accounts for all components of the TOF including cables and their connections. Tables in the database account for the following:

  1. Modules
  2. PMTs
  3. Signal cables
  4. Splitters
  5. ADC cables
  6. ADCs
  7. Discriminator cables
  8. Discriminators
  9. TDC cables
  10. TDCs
  11. HV cables
  12. HV cards

He relies on spreadsheets obtained from Nick Sandoval for all of the cable connections. The database for TOF II (upgraded configuration) is complete. That for TOF I (legacy configuration) still needs a few components (but is by now an academic exercise).

Database queries can be composed to generate several different views of the data. Mark showed three examples, all generated with a one-line query:

  1. Module/PMT map for TOF I
  2. Module/PMT map for TOF II
  3. Crate/slot/channel map for TOF II ADCs

A new, independent labeling scheme is introduced, which is oriented toward reconstruction:

  • "H" or "V" for horizontally oriented modules or vertically oriented modules
  • "01" to "46" for the 46 PMTs along an edge, running from negative x (or y) to positive x (or y) in the global GlueX coordinates
  • "+" or "-", + for the positive end of the module in x (or y), - for the negative end

Example (3) can be used to generate the translation table for ADC read-out. Similar tables can be generated for the HV and the TDCs electronic channel maps.

Monte Carlo Status

Ashley reports that there is still a problem with HDGeant4 vis-a-vis the upgraded TOF. See HDGeant4 Issue #123, "TOF geometry generalization."

TOF NIM paper

Beni encouraged Sasha to start writing up the section on module testing and certification. Sasha will prepare a draft by next week.