Feb 25, 2010 Readout

Teleconference Time: 11:00 a.m. EST

• ESNET and EVO session
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Items for followup from previous meeting

1. Testing of new cal modules to measure light output and determine the range of photoelectrons expected (George to propose test plan) start with construction prototype and existing equipment
2. Input/Decisions needed to finalize Bcal readout requirements (See also GlueX-doc-1373).
   • Specify the normalization and dynamic range for the number of photons/GeV in showers (Andrei to summarize MC results) - definition of simulation runs under discussion
     • charged particles should also be included into the evaluation
   • Decide on specific grouping for SiPM sums studies will be done with output of simulation runs.
   • Possibility of using air gap for SiPM coupling to light guide (Elton to write up results)
   • Finalize shapes of "Winston guides" progress and more discussion

Documents to Review

1. • See GlueX-doc-1300 Evaluation of Bcal Readout Options
   • See GlueX-doc-1301 Energy Resolution and Output Signals Simulation for Detailed-Structure BCAL Module Model

Tentative Agenda

1. Announcements
2. Review of Action Items
3. Simulation Proposal and Elton's remarks Discussion (Zisis)
4. Update - USM
   • Plot of SiPM measurement at USM
5. SiPM - update
   • Plans for testing radiation damage in Hall A
6. Geometry
7. Light guides
   • See GlueX-doc-1432
8. Discussion - MOU with USM

Minutes

Attending: Zisis, George, Andrei (UofR); Elton, Eugene, John, Pedro, Beni, Yi, Lubomir, Fernando; Will (USM).

1. Announcements
2. Review of Action Items
   • Test plan for measuring parameters with new modules. Proposal is to start with the construction prototype, pmts and existing Winston Cones. Later one can change out the readout for SiPM arrays.
   • SiPM arrays have been received and Kathryn will transfer information to Stamatis, as she will be leaving soon.
   • At the appropriate time, one of the production modules might be kept at Regina for further prototyping and tests.
3. Simulation Proposal and Elton's remarks Discussion (Zisis)
   • Each of the items was discussed and feedback was given to Zisis
   • New (as built) geometry will be used to update model
   • Discussion of using 2 component attenuation length
   • Grouping of SiPM into summing groups is done externally to the simulations and various groups, especially in the outer layers, will be studied one the simulations are complete.
4. Update - USM
   • Plot of SiPM measurement at USM
   • USM presented their first spectra from a 3x3 Hamamatsu SiPM. There were many questions, but it is great to see this first step. Further discussion next week.
5. SiPM - update
   • Plans for testing radiation damage in Hall A
   • Plan was discussed.
   • Eugene suggested moving all the electronic equipment out of the hall if possible.
   • Several measurements of the neutron flux would be useful for normalization.
   • Will said that the 2-photon experiment in Hall B had borrowed 4 calibrated neutron detectors based on liquid scintillator from the U. of Washington. If they have not been returned, they might be available for this test. We will check with Doug Tilles and/or Dave Kashy. (Charles Hyde was the contact for the detectors).
6. Geometry
   • Chuck Hutton is working on implementing the geometry into the solid model. Should report at the next meeting.
7. Light guides
   • See GlueX-doc-1432
   • Segmentation of the light guides was tentatively endorsed. No one foresaw specific issues with it.
   • Elton discussed results of simulations and there was considerable discussion.
   • Some ideas that were discussed included:
     • use soft glue to fill gaps between light guide and sensor
     • ignore "cross talk" between light guides to collect more light in the case of a gap between Bcal and light guide.
   • Additional studies suggested: dependence of collection on length of guide and collection for the case with an air gap at each end.
8. Discussion - MOU with USM
   • Will, Serguei and Elton talked on the phone earlier this week and reviewed the current MOU. There will be a meeting with the 12 GeV management on Monday to discuss the current draft.