GlueX TOF Meeting, February 9, 2022

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GlueX Time-of-Flight Meeting
Wednesday, February 9, 2022
11:00 am EST

Zoom Meeting ID: 160 345 9418, Passcode: 080357

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  1. Announcements
  2. Review of minutes from the last meeting
  3. Long-Term Detector Health (Sasha)
  4. TOF II Trigger
  5. TOF NIM paper
  6. Action Item Recap


Present: Eugene Chudakov, Paul Eugenio, Mark Ito (chair), Sasha Ostrovidov, Simon Taylor, Beni Zihlmann

There is a recording of this meeting on the ZoomGov site. Use passcode: xut*x!b8 .

Review of minutes from the last meeting

We went over the minutes from the meeting on January 26th.

Paul reported on a few points related to the equipment loan.

  • Edmundo Barriga is stationed in Newport News, but will be traveling to Tallahassee for the collaboration meeting. He will pick up some items covered by the loan agreement, including the VXS crate, and bring them back to the Lab.
  • The bulk of the remaining items are the spare PMTs.

Long-Term Detector Health

Sasha presented work he has done to assess the lifetime of the TOF, in particular the degradation of PMT gain as a function of time/beam-exposure. See his slides for the details.

Some items from the discussion:

  • Beni: specs on PMT gain as a function of integrated charge on the last dynode is provided by Hamamatsu. Integrated charge, in turn, can be estimated by the from the time integrated rate of minimizing particles.
  • Paul: we learned a lot from the PMT-relacement exercise last year. A strategy of identifying weak tubes and replacing them will help maintain uniform acceptance of the array.
  • Beni: he identified candidates for replacement last year in part by noting PMTs that did not respond with the expected amount of increased gain with increased voltage during gain balancing.
  • Eugene: in general, there are other sources of gain loss besides degradation of the last dynode, including damage to the scintillators (surface crazing, radiation damage) and damage to the voltage ladder in the PMT base.
  • Sasha could use a table of the correspondence between read-out channel and HV channel. Mark will query his database for this information.

Much of this material will be presented at the upcoming Collaboration Meeting.

TOF II Trigger

Beni reported that this month has been reserved for Sascha Somov to do tests on the TOF II trigger.