April 8, 2010 Readout

Teleconference Time: 11:00 a.m. EST

• ESNET and EVO session
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• Phone:
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Items for followup from previous meeting

1. Input/Decisions needed to finalize Bcal readout requirements (See also GlueX-doc-1373). (Ongoing)
2. Serguei agreed to send out a testing proposal for comments, including preliminary circuit designs and list of available equipment at USM for reference.
3. Fill out loan agreement for SiPM arrays at UofR (Elton).
4. Start a bulleted list of testing for the SiPMs (Serguey).

Tentative Agenda

1. Announcements
2. Review of Action Items
3. Update - USM
4. Simulation runs (Media:Bcal_fluka_100408.pdf)
5. Geometry
6. SiPM Radiation Hardness Test (Yi)
7. SiPM - Testing Schedules
8. Light guides

Minutes

Attending: Andrei, George (UofR); Elton, Fernando, Yi, Beni, Eugene (Jlab); Serguei joining later (USM)

1. Announcements
2. Review of Action Items
3. Update - USM
   1. None at this time. Approximately 35% of work completed. Will pass drafts to Elton and Fernando next week for feedback. Will discuss at the next Bcal readout meeting.
4. Simulation runs (Media:Bcal_fluka_100408.pdf) Main purpose of study is to establish dynamic range for readout
   1. Reviewed updated (final) geometry including magnetic field and top (i.e. inner) 8 mm Al plate.
   2. Runs completed include 2.5 GeV at 12 deg (30 cm from downstream end) and phi=0. 2.5 GeV at 14deg; 0.06 MeV at 105 deg (30 cm from upstream end)
   3. Presentation showed energy deposition and expected number of photoelecgtrons in upstream and downstream detectors.
   4. Currently running 2.5 GeV centered on the middle of one readout channel (phi nonzero).
   5. The detailed information about light collection in each cell is available, so other segmentations can easily be produced.
   6. Asymmetry in shower development noticible due to magnetic field. Eugene: This will have a systematic impact on the phi coordinate measurement.
   7. Preliminary estimates show that there is considerable amount of light. Eugene: could consider a green filter to soften the exponential attenuation in the module. Elton: If photon yield can be reduced, we should reconsider putting a gap between the light guide and sensor to ease mechanical construction.
5. Geometry
6. SiPM Radiation Hardness Test (Yi)
   1. Checked setup. It is ready to go. Readout includes temperature, voltages and dose rates
   2. Hall A is presently down due to a leak in the scattering chamber and production running will be delayed till next week. Will wait for stable running before starting systematic irradiation of SiPMs.
7. SiPM - Testing Schedules
   1. Fernando: Developing pre-amps for 1 mm2, 3mm2 and arrays. 1mm2 and arrays are available to assist in testing. Will check with Carl to see if a 3mm2 single is available. Otherwise a pair will be ordered from Hamamatsu for use in developing electronics.
8. Light guides
   1. No report.