GlueX TOF Meeting, September 8, 2015

From GlueXWiki
Revision as of 10:12, 9 September 2015 by Marki (Talk | contribs) (add the minutes)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

GlueX Time-of-Flight Meeting
Tuesday, September 8, 2015
11:00 am EDT
JLab: CEBAF Center, Room F326/327


  1. Announcements
  2. Review of minutes from August 25
  3. Calibration Status FSU
  4. Calibration Status JLab



Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2015 on the JLab CUE. This directory is accessible from the web at .



  • FSU: Hussein Al Ghoul, Brad Cannon, Paul Eugenio, Sasha Ostrovidov, Aristeidis Tsaris
  • JLab: Mark Ito (chair), Simon Taylor, Beni Zihlmann


The run date is likely to be in December, though nothing is certain.

Review of minutes from August 25

We looked at the minutes.

ADC charge resolution and NSB/NSA

  • Beni updated his plots and posted them in the logbook. He also included an example of a fit to the MIP peak and an example waveform.
  • Sasha asked about conclusions drawn from the study. Beni thought we should probably leave NSB at 5 but shorten NSA from 50 to 30.
  • Sasha was concerned about the effect on large pulses when the tail is cut-off, for example when studying attenuation. Beni pointed out that in the limit that all pulses are the same shape (geometrically similar) the small pulses have the same fraction of tail area cut out.

Gain vs. High Voltage

  • Gains measured at FSU were all done at 1750 V. We might want to measure the exponent of the dependence of gain on HV with the installed system. Sasha is going to try and do that.

Cosmic Running in the Hall

Sasha talked to Sascha Somov today. He (Somov) will get the TOF stand-alone trigger going sometime today.

Calibration Automation

Brad is completely done with the system for running timing calibration jobs. He sent his constants to Beni and he put them in a private calibration variation. Using the constants reproduced essentially the same resolution those Beni had obtained some time ago.

We would like to run the system on new data as soon as it becomes available. We might think of an online system as well. Unfortunately the method depends on having beam data; cosmic data is not useful for this purpose.


Beni has been looking at the code. He sees that there is a configuration parameter that can be set to analyze cosmic data, that could change values. Aristeidis implemented this branch of analysis in the early installation and testing weeks. We need to evaluate whether we want to continue to maintain it.

Energy Calibration

Beni continues to look at attenuation and gain calibration issues.