GlueX Start Counter Meeting, December 9, 2021

From GlueXWiki
Jump to: navigation, search

GlueX Start Counter Meeting
Thursday, December 9, 2021
10:00 am EST
BlueJeans: 556 286 544


  1. Announcements
  2. Review of minutes from the last meeting
  3. Run report
  4. Resolution and Calibration
  5. Action Item Review


Present: Eugene Chudakov, Mark Ito, Igal Jaegle, Simon Taylor, Beni Zihlmann

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

Review of minutes from the last meeting

We went over the minutes from the meeting on October 14th without significant comment.

Run report

Beni showed evidence of increased dark noise in the SiPMs. He looks at a statistic that is sensitive to a high-side tail of the pedestal distribution taken from beam-off data in raw mode. The higher the dark noise, the lower the statistic. This measure was explained at a previous start counter meeting. There is a clear trend, year-to-year, of increased dark noise.

Paddle response p1.gif
Pedestal distributions showing high-side tails.

Sc darkratetest.gif
Statistic as a function of run number

We discussed possible ameliorations, including replacing the SiPMs. We are nowhere near deciding on that course of action; more study is needed.


Mark will try to round up some volunteers to calibrate the start counter for the PrimEx and SRC runs.