Jul 26, 2011 Readout

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Teleconference Time: 11:00 a.m. EST

  • ESNET 8542553 and EVO session
  • JLab Phone: in CC F326 is 757-269-6337 (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
  • Phone:
    • +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)

Items for followup from previous meeting

  1. Gap efficiency
    • Generate efficiency plots for nominal configuration before inclusion of readout elements DocDB-1789
      • Browsing the histograms:
      • current BCAL geometry implementation is not according to drawings.
    • Generate efficiency for typical reactions
    • Study effect of moving 4th plane upstream by 20 cm on tracking

Documents to Review

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Monitoring Update (Athens)
  4. USM Update
  5. SiPM update
  6. Electrical/cooling (Elton)
  7. Geometry and light guides
  8. Simulations

Minutes

Attending: Tim, Elton, John, Yi, Beni, Eugene (JLab); Andrei (UofR); Will (attempted connection but was unable to join).

  1. Announcements
  2. Review of Action Items
  3. Monitoring Update (Athens)
  4. USM Update (Notes sent by Will since he was unable to connect)
    1. Prototype boards: both boards fully stuffed with components, fully tested with current injection pulses, and mounted on the dark box, following installation of the 4 patchthrough boards. Light-based measurements, with cooling circuit active, will begin this week.
    2. Some small areas of the boards are not working. The amplifiers work fine, but some pins of a few multiplexers don't seem to have good connection. The belief is that there are bad solder joints on a few pins. This will be investigated further this week, but it does not prevent light-based testing.
    3. Currently we can test 8 MPPCs at once.
    4. The 10 MPPCs on loan from JLab arrived with no visible damage. There was a long holdup in customs.
    5. The new, more modular boards are under construction. These hold 8 amplifiers and 1 multiplexer. We could fabricate some for JLab tests if desired. Using those, the big board only has traces, some logic, and power supplies. This will allow for faster switchouts of components when needed.
    6. PDE measurements setup:
      • Light mixer has been prepared - splits light uniformly from 1 clear fiber to cylinder 60 mm diameter x 100 mm length, with the far end painted with white paint. 18 green fibers, with depth 20 mm, implanted into the same end as the clear fiber, so light bounces at least once before hitting the 18 green fibers. Performance will be tested starting this week.
  5. SiPM update
  6. Electrical/cooling (Elton)
    • Fernando has shortened the rise time of the SiPM array output by adding a capacitor to the bias lead on the "U" board. However the shape of the pulses are not fully understood and appear to have a two component fall time. He is working on the amplifier circuit this week.
  7. Geometry and light guides
  8. Simulations. Study of the Gap Efficiency (Beni)
    1. Generate efficiency plots for nominal configuration before inclusion of readout elements DocDB-1789
      • Browsing the histograms:
      • current BCAL geometry implementation is not according to drawings.
      • Generate efficiency for typical reactions
    2. Study effect of moving 4th plane upstream by 20 cm on tracking
    3. Discussion of the study to date
      • Updated GlueX doc note added comparisons of new readout geometry to original default geometry
      • Added study of cables routed downstream as well as comparison of cooling plate using Cu vs Al
      • Eugene: noted again that some benchmark reactions would be processed to evaluate a average figure of merit for each configuration (e.g. average acceptance)