Feb 19, 2009 Calorimetry

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Teleconference Time: 11:00 EST/10:00 CST

  • Phone:
    • +1-800-377-8846 : US
    • +1-888-276-7715 : Canada
    • +1-302-709-8424 : International
    • then enter participant code: 39527048# (remember the "#")

Items for followup from Feb 12 meeting

  1. Resolution studies (Blake)
    • Develop criteria for evaluating resolution studies
    • Study impact of inactive material at the end of BCAL on acceptance.
    • Check what configuration (thresholds, step sizes, stack? parameters for secondaries, etc) is being used for the Hall D simulations (Regina)
  2. Elton, Matt and Zisis to send information regarding tools which have been used for studying light collection. See: Light Guide Information
  3. Review options for import/export to Chile (loans, donations, transfers, etc.)
  4. Matt: Add hooks to code so that DR and PDE can be provided as input parameters.

Documents to Review

Tentative Agenda

  1. Announcements
  2. FCAL Update
  3. Simulations (Blake et al)
    1. February 17, 2009 Physics with updates
  4. BCAL Update
    1. Bcal construction
  5. BCAL Readout
    1. First look at first article fibers (Beni)
    2. Update on SiPM tests
  6. Review of Action Items


Attendees: Elton, Tim, Beni, Carl (JLab), Matt (Indiana), Hayk + 4 students (USM), Andrei, Blake, George, Zisis (Regina)

  1. Announcements: Elke completes her tenure with Hall-D/GlueX on February 27.
  2. FCAL: Matt gave the FCAL update.
    1. Next iteration on MOU is waiting to check manpower numbers. Will revise and send to Elke (and Tim, Eugene, Elton).
    2. Jake, student working on the Flash has been reassigned to test pmts in magnetic fiels with the Helmholtz coil. Study is to see if it is possible to shorten iron shield at the back of the tube without significantly affecting performance. It will be good to also refine the magnetic shielding calculations by ANSYS for best estimates of magnetic field at the location of the Fcal. (Tim mentioned that Bill Crahen will be looking into these calculations.)
  3. Reconstruction: Blake presented his work and list of future tasks, and addressed questions. Blake presented these results and tasks were discussed during the reconstruction meeting on Feb 17, with Matt, Ryan and Zisis.A discussion ensued to clarify the definition and value of the threshold. Matt reported that he has written the code to determine the BCAL threshold based on 7 parameters that include the Dark Rate, gate width, no. of pe, PDE, etc. The code will be tested soon and checked into the repository after that. Will also prepare a document to describe the work.
  4. BCAL construction: George reported that the Dean of Science looked at the new version of the MOU and found the changes suggested by Allison to be reasonable. The Office of Research Services will look at it next (later in the day we found out that this will be looked at on Monday).
  5. BCAL Readout:
    1. Beni reported on tests of the three of the first article fibers, using his setup, a stronger 90Sr source (25 uCi) and the 'old' collimator with the wide slit. The appear to meet our specifications to Kuraray on no of p.e. and attenuation length. Beni plans to test all 50 fibers in this manner, but with a new, narrower collimator. Some refinements to the fitting code are needed. Zisis explained that once the Regina fibers arrive (they arrived at JLab today and will be shipped out asap) 25 will be tested for attenuation length with the spectrophotometer (unless discrepancies appear and then all 50 will be examined), all 25 will be tested with 90Sr for their no of p.e. at 200cm, and a handful will undergo an attenuation length scan with the radioactive source (100 uCi). The new components for the spectrophotometer scans have been completed by Danny at the machine shop.
    2. (Note added by Elton:) The 50 fibers slated for Regina arrived at JLab in a damaged box. Beni said that from a visual inspection the fibers seemed to be ok, but pictures were taken to record the state of the box. 20 fibers from the JLab batch (undamaged) and 30 from the damaged box will be packaged into the JLab undamaged box for shipment to Regina.
    3. Carl briefly presented his uniformity scans of the pixellated arrays. He will present his results and any new ones in more detail at our next meeting.
  6. A review of the action items was postponed until the next meeting, when more people would be present. Zisis marked the completed items.