Apr 30,2013 Readout

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Teleconference Time: 11:00 a.m. EST

  • ESNET (Number is 8542553) and EVO session (GlueX Calorimetry meeting room)
  • Phone connection only upon request.
    • +1-866-740-1260 : US and Canada
    • +1-303-248-0285 : International
    • then use participant code: 3421244# (the # is needed when using the phone)
    • OR from www.readytalk.com type access code 3421244 into "join a meeting" without the # (you need java plugin)

Participant Direct Lines

  • JLab Phone: in CC F326 is 757-269-6460 (usual room)
  • JLab Phone in CC L207 is 757-269-7084
  • Phone in the Regina Videoconference Suite is 306-585-4204
  • Athens Phone: in Christina's office is 011-30-210-727-6947

Items for followup from previous meeting

Presentations from recent meetings

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Monitoring
  4. Status of testing at Regina
  5. Update from JLab
  6. Update from USM
  7. Beam Tests, Cosmics
  8. Reconstruction and simulation
  9. Other


Attending: Elton, David, Beni (JLab); Christina, George Vasileiadis (Athens); Shaun, Zisis, Andrei (UofR); Will, Alam, Elias, Serguei (USM)

  1. Announcements
  2. Review of Action Items
  3. Monitoring (FCAL)
    • George has finished testing 50 LED boards.
    • There are 4 control boards and 4x10 LED boars with one extra set.
    • Plots of results will be sent out this week and presented at next Tuesday's Cal Working group meeting.
    • Expect to be able to ship electronics, along with a sample of the plexiglas sheet, next week after feedback from the presentation.
  4. Status of testing at Regina
    • PDE measurements at UofR have been completed and the data are being checked
    • Should be able to return the SiPMs this week
  5. Update from JLab
    1. Completed about 32 modules
      • Old procedure has resulted in light guides detaching from the face of the module.
      • A survey of modules in the hall has found 2-3 modules with large number of failures. Most other modules have some issues, but with limited number of light guides
      • Many of these modules will have to be reworked.
      • Waiting on qualifying a new procedure before starting major repairs.
    2. A new procedure for gluing has been developed
      • The procedure includes: a) sanding the base of the guide b) shining light into the light guides from the top side (fixture in place) so that they hold c) complete curing by shinning light from the top end (after removing the fixture) for 50 s. Based on measurements of the light source, this time should deliver more than 6 J/cm2, where the estimated cure energy density is 2.5 J/cm2.
      • Two modules have been completed this way and they appear healthy at this time.
      • After qualifying the new procedure, we will illuminate the modules in the hall once again to ensure that the glue is cured.
      • Modules with remaining issues will be repaired under the new process.
    3. Transmission tests
      • System to measure the transmission of light from an LED through each light guide from one end to the other has been implemented.
      • The goal is to see if this can be sensitive to gluing failures. The variation seen in a good module is on the order of +/-15%, which is the expected change in transmission for detached light guide.
      • The transmission tests seem to be reproducible at the percent level by comparing upstream and downstream measurements, as well as by spot checking a few channels for reproducibility.
      • The measurement system could prove useful in checking changes over time.
    4. Questions:
      • Zisis: How many modules are on the cradle? The cradle is now fully stacked for load testing (about half the modules), but not all modules have been aligned. Some may have to be taken down for repairs.
      • Will: Inquired about the radiation hardness of the glue (previous experience resulted in a darkening of a glue he used). Elton: Will check.
  6. Update from USM (Light guides)
    • JLab is preparing to return 110 light guides for rework
    • Alison is preparing the paperwork for customs
    • Serguei: At the moment there are 99 replacement light guides. The production is stopped to install new equipment and will be down for about 2 weeks.
    • Estimate to be able to send replacement light guides by the end of May
    • Elton: It might be possible to rework some of the returned guides when they are oversized.
    • Elton: Noticed machine marks on some guides, likely from the milling machine and a photo was e-mailed to USM to investigate problem. Could be due incomplete polishing during training.
  7. SiPMs
    • The three non-conforming SiPMs were shipped back to Hamamatsu and they are being evaluated at the factory.
    • Elton will check on status.
  8. Beam Tests, Cosmics (Shaun)
    • ROOT script to process cosmic tests has been modified to optimize the integration window.
    • Starting to analyze the runs with double trigger scintillators
    • Elton: Should get a version that can be run on all modules to check if there are any anomalies
  9. Reconstruction and simulation
    • Zisis: Not much progress in the last weeks. Will meet Thursday to check progress, establish priorities and a timetable.
  10. Other
    • Elton: Request that everyone with borrowed SiPMs return them to JLab.