GlueX Start Counter Meeting, July 9, 2020

From GlueXWiki
Jump to: navigation, search

GlueX Start Counter Meeting
Thursday, Julu 9, 2020
10:00 am EDT
BlueJeans: 556 286 544


  1. Announcements
  2. Review minutes from the last meeting
  3. Calibration and Efficiency
  4. Dark Rate Studies
  5. Action Item Review


Present: Rupesh Dotel, Tolga Erbora, Mark Ito (chair), Susan Schadmand, Simon Taylor, Beni Zihlmann

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


Beni has turned on the start counter and taken a cosmic ray run. I quick glance at the data showed the start counter data missing, but this needs confirmation and review of the DAQ configuration.

Review of minutes from the last meeting

We went over the minutes from June 25.

Fernando wrote a message to the email list on possible replacement of the SiPMs. He thinks it is marginally easier to replace a whole board rather than replacing individual SiPMs (12 per board). He also pointed out that we have a couple of spare units in hand.

Beni asked if the SiPMs are the same as those used for the pair spectrometer. Mark will check.

Run Readiness

Beni is getting ready to check signals and pedestals in preparation for Hot Check-out and the run.

Calibration and Efficiency

Werner Boeglin has asked Rupesh to look at the ADC response of the start counter in light of the possible degradation of timing resolution during the course of the last run. We spent some time going over how this might be done. Rupesh showed plots from a plugin that Mahmoud Kamel pointed out to him that plots ADC spectra for individual channels.

Action Item Review

  1. Document calibration procedure (Rupesh)
  2. Reproduce Beni's dark current results. (Tolga)
  3. Check status of the gain calibrations using monitoring histograms. (Rupesh, Beni)
  4. Revisit Yi's study of SiPM annealing. (Mark, Beni)
  5. Ask about the current recommendation from SciComp on copying files to the local disk from cache before analyzing them. (Mark)
  6. Look up type of SiPMs used in start counter. (Mark)