Mar 25, 2010 Readout

From GlueXWiki
Jump to: navigation, search

Teleconference Time: 11:00 a.m. EST

  • ESNET and EVO session
  • Phone in CC F326 is 757-269-6337
  • Phone:
    • +1-800-377-8846 : US
    • +1-888-276-7715 : Canada
    • +1-302-709-8424 : International
    • then enter participant code: 77438230# (remember the "#"). Phone connection only upon request.

Items for followup from previous meeting

  1. Input/Decisions needed to finalize Bcal readout requirements (See also GlueX-doc-1373).
    • Define set of simulations run needed to determine dynamic range of SiPMs
  2. Serguei agreed to send out a testing proposal for comments, including preliminary circuit designs and list of available equipment at USM for reference.

Documents to Review

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Update - USM
  4. Simulation runs
    • 7.93-mm top Al plate (with correspondent glue pockets) is added into FLUKA geometry
    • Magnetic Field Map ANSYS 20081209-1_1500.dat; linear interpolation between the grid points
    • Double-exponent formula for light attenuation; about 20-25% effect for close-to-readout-end hits
    • Ready to start the simulation as soon as the Momentum-Angle table will be specified.
  5. Geometry
  6. SiPM Radiation Hardness Test (Yi)
  7. SiPM - Testing
  8. SiPM - production testing
    • Schedules
  9. Light guides

Minutes

Attending: Fernando, Yi, Chuck, Tim, Beni, Elton, Sasha (JLab); Serguei (USM); Zisis, George, Andrei (UofR)

  1. Announcements
  2. Review of Action Items
  3. Update - USM
    1. Purchasing new equipment and setup
      • CAEN equipment
      • Design/buid box for SiPM test including thermal stabilization
      • Establishing procedure to measure VI curves
      • Finding that significant stabilization time for sensor required of about 30 min. Two component exponential with tau1~ 5 s and tau2~30-40 min. Will have results for next meeting.
      • Elton asked about noise from LED. Serguei said that this is simply low level noise (~2mV) in the box, which made it difficult to have sensitivity to single p.e. peak.
      • Finding different rise times using different amplifier impedance. Mentioned that 3x3 mm2 unit has capacitance of 300 pf (Fernando verified this at the end of the meeting).
    2. Amplifier circuit
      • Fernando mentioned that Carl has received some 1mm2 samples from Hamamatsu for evaluation. They will start using the amplifier that Stepan used in Hall B. Fernando will develop a circuit for these single-cell units. He thougth that a common circuit could be used for the 1mm2 and the 9mm2 units.
    3. Testing of array at UofR. They are setting up the tests. Elton mentioned that we should fill out a loan agreement.
  4. Simulation runs
    1. Setup so far
      • 7.93-mm top Al plate (with correspondent glue pockets) is added into FLUKA geometry
      • Magnetic Field Map ANSYS 20081209-1_1500.dat; linear interpolation between the grid points
      • Double-exponent formula for light attenuation; about 20-25% effect for close-to-readout-end hits
      • Ready to start the simulation as soon as the Momentum-Angle table will be specified.
    2. Discussion of runs needed
      1. Pythia Plots: Media:mom_gamma_log_BCAL.png and Media:momVStheta_gamma_log.png
        • Downstream: Tentative agreement to use Emax=2.5 GeV. Blake to check distribution for eta-pi0 distribution. For the angle, Elton suggested 30 cm from the downstream end, rather than the angle for the maximum depth. Regina will check effect of losses out the front.
        • Upstream: Suggestion is to take the angle corresponding to the position 30 cm from the end and Emin=60 MeV.
        • Parameters: At the moment the parameters for naked fibers are used. Acceptance for the double clad vs single clad fibers inbedded in glue was discussed. Elton said it dependended on the indeces of refraction, George contented it was thickness of layers.....
  5. Geometry
    1. [http:www.jlab.org/~huttonc New geometry] (Chuck)
      • Update explores methods to make system light tight.
      • Serguei suggested 3M reflective film (60-90 micons thick) could be used in region where light guides are in contact. (Can also contact Yuri Sharabian).
  6. SiPM Radiation Hardness Test (Yi)
    1. System preparation are almost complete. Hall A expects production running in about 10 days, when the tests will be conducted.
  7. SiPM - Testing schedule
    1. Will start with bulleted list (Serguei) and proceed from there.
  8. Light guides - no update.