Mar 29, 2011 Calorimetry

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Teleconference Time: 11:00 a.m. EST

  • ESNET (Number is 8542553) and EVO session (GlueX Calorimetry meeting room)
  • JLab Phone: in CC F326 is 757-269-6337
  • Regina Phone: in LB228 is 306-585-4204
  • Athens Phone: in Christina's office is 011-30-210-727-6947
  • Phone connection only upon request.
    • +1-866-740-1260 : US+Canada
    • +1-303-248-0285 : International
    • then enter participant code: 3421244# (remember the "#").
    • or (and code without the #)

Items for followup from previous meeting(s)

  1. Monitoring
    • Fcal: check cross talk of calibration inputs across modules.
  2. Simulation
      • Need to study the reconstruction efficiency.
      • Andrei will send David instructions for using summing and configuration files.

Tentative Agenda

  1. Announcements
    • Starting this week, we will move the Bcal Readout meeting and Cal Working Group meetings to TUESDAY 11:00
  2. Review of Action Items
  3. Calibration
  4. FCAL
    1. Construction Status: mechanical, bases
    2. Drawings for Fcal structure (Tim)
  5. BCAL
    1. Construction Status: builds, fibre QA
    2. First article testing (Yi)
  6. Simulations


Attending: Beni, Elton, John, Eugene, Tim, Lubomir, Yi (JLab); Will, Serguei (USM); Matt (IU); Zisis, Andrei (UofR).

  1. Announcements
    • Starting this week, we will move the Bcal Readout meeting and Cal Working Group meetings to TUESDAY 11:00
  2. Review of Action Items
  3. Calibration
  4. FCAL
    1. Construction Status: mechanical, bases
      • John and Steve have completed wrapping blocks. Shipment expected about April 18.
      • Bases Status; Only 5 non-operational out of 500. 2 have a low clock speed creating difficulties communicating with CAN bus.
      • 400 bases connected to CAN bus and operating smoothly
      • Investigating what is poor assembly in preparation for order of 2500 remaining bases
      • Company that built the 500 is increasing rates for the next 2500. IU is investigating options for bidding the large order, including possibly changing vendors.
      • Discussions are ongoing related to CAN interface to slow control system
    2. Drawings for Fcal structure (Tim) Sketches for comments on FCAL structure
      • Discussions on mechanical design completed with Tim and Wayne.
      • Prototype under construction to validate the design.
      • The beefed up structure, which allows the structure to be lifted whole, will be incorporated into the John's drawing package
  5. BCAL
    1. Construction Status: builds, fibre QA
      • Production all normal.
      • Shipment of fibers arrived last week
      • Modules 33-34 will be completed next week
      • Machining of modules 24-28 proceeding well. Expect shipping to JLab second week of April, with 8th shipment following 2 weeks later.
    2. First article testing (Yi)
      • Completed testing 40 units
      • Checked calibration of QDC. Gain of samples is about 6x10^5 instead of 7.5^10^5, expected for nominal Hamamatsu voltages.
      • Measured the gain vs voltage for normalization
      • For increased gain, the dark rates increase by about 30-40%, still below the rates from the original samples
      • Results are being updated with calibrated gains.
      • Tim: Check the apparatus with early samples to qualify test setup.
      • After verifying that all checks have been completed, send 10 units to UofR and 10 to USM.
      • Proceed with radiation tests of several samples to check response compared to previous samples.
  6. Study of BCal Segmentation with BCal Reconstruction Code. Part 2: Angular Resolution (A.Semenov for UofR group)
    1. Studied angular resolution, assuming known vertex (center of target)
      • Reconstructed theta angle for summed configuration about 2x worse than for fine segmentation
      • Reconstructed phi angle about the same for both summed and fine segmentations
      • Beni: How is the timing determined for summed configuration? Matt: times are energy weighted averages of the time of individual cells
      • Matt: Noted that recent discussions on listservers noted that the function of the primary flag has changed. Does not think it would change results, but should be verified
      • Eugene: At 90deg the timing of both situations should be very similar, but are not. Suggest checking this configuration, and once understood, moving to other cases
    2. Elton: Asked whether the efficiency of reconstruction has been investigated. Andrei: not yet
      • Matt: On the efficiency of reconstruction: Mihajlo studied this effect when the FDC design was being finalized. These results could be used as a reference. Of course, no study involving summing has been done yet.
    3. Andrei: Careful control of software versions should be considered and documented, and extended to the use of flags. Studies should attempt to use tagged versions only.
      • Matt: It is possible to use the revision number for any checkout from the repository as an identifier, although tagged releases are in fact preferable, because these are usually more stable.
    4. New reconstruction code (Matt)
      • Matt has written and checked new code for clusterizing. However, it is not yet tuned