GlueX TOF Meeting, November 07, 2013

From GlueXWiki
Jump to: navigation, search

GlueX Time-of-Flight Meeting
Thursday, November 7, 2013
10:00 am EST
JLab: CEBAF Center, F326/327


  1. Announcements
  2. Review of meeting on October 10
  3. Construction News
  4. Testing Update
  5. Time-of-Flight Calibrations
  6. Installation plan
  7. Amplifiers for high rate counters?



  1. ESNet: 8542553

Desktop Sharing

  1. Go to
  2. In the "join a meeting" box enter the code: 1833622
  3. Fill in the participant registration form.


To connect by telephone:

  1. dial:
  2. enter access code followed by the # sign: 1833622#


Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2013-4Q on the JLab CUE. This directory is accessible from the web at .



  • FSU: Sasha Ostrovidov
  • JLab: Hussein Al Ghoul, Eugene Chudakov, Paul Eugenio, Mark Ito (chair), Aristeidis Tsaris, Beni Zihlmann
  • Northwestern: Sean Dobbs

Find a recording of the meeting here.

TOF Delivery

Find some photos here.

  • Paul, Hussein and Aristeidis drove 6 crates of modules up from FSU and stored them in the ESB yesterday. They inspected modules in two of the crates and they look like they made the trip totally intact. Each crate holds 8 modules. These are all standard modules. There 5 more crates to transport. Those will come in a couple of weeks.
  • FSU also delivered the the steel shields that were made by the machine shop there. This is all of them.
  • When the last 5 crates of modules are transported, FSU will also bring the collars, stand-offs, and Swiss cheese blocks. All of the parts are made except for the stand-offs, which are near complete.
  • They will also bring equipment to test the modules here, including a crate, HV supply, and a scope.
  • FSU would like to have a small locker or set of shelves in the Hall or Counting House to store tools, such as the tube removal device.
  • We will check with Tim to make sure that floor space in the Hall for assembly is in his plan. [Added in press: it is.]
  • Congratulations to FSU for achieving this important milestone!

Module Testing

Sasha reported that the testing of all 92 modules is now complete, including the half-length and half-width modules, of course. See his web page for details. He covered the following topics:

  • Status of TOF module tests
  • HV balancing for short modules
  • Issue with time walk correction fit


Sasha led us through the talk he gave last year on calibration, outlining the thinking at that time. See his slides for details. The plan is in six steps

  • Step 1: TDC / ADC calibration
  • Step 2: PMT gain balancing and monitoring
  • Step 3: Time-walk corrections
  • Step 4: Single-paddle left/right adjustment
  • Step 5: Paddle-to-paddle timing offsets
  • Step 6: Fit of TOF time to RF time

Sean is pushing each detector group to list the sets of calibration constants that will be needed. We can then work backwards to the procedures necessary to measure these constants. Sasha volunteered to draft a list for us.