Feb 24, 2011 Readout
From GlueXWiki
Teleconference Time: 10:30 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
- 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)
Contents
Items for followup from previous meeting
-
Update on simulation with summed cells (Andrei and Irina) -
Update Document Control at JLab with signed copies of QA (UofR), QC/QA (IU), and procedures for signoff of non-conforming items (Elton and Tim). -
Plot the angular distribution of pi0 and etas (Elton)
Documents to Review
Tentative Agenda
- Announcements
- Review of Action Items
- USM update
- SiPM update
- First Article testing
- Simulations
- Electronics/cooling
- Geometry and light guides
- Monitoring system light injection: Media:athens_led_fiber.pdf
Minutes
Attending:Elton, Beni, John, Tim, Yi, David, Eugene (Jlab); Zisis (UofR); Will (USM)
- Announcements
- Review of Action Items
- USM update
- Box shell for testing is complete, including Cu cooling plate and holes for SiPMs
- Working on the response to JLab solicitation
- Exchanges with Hamamatsu ongoing
- Some concerns regarding risk of payment in FY12, but working through them
- There is one 1000 piece delivery (the first) vs regular 500 piece deliveries which is under discussion with Hamamatsu
- Light guide (2 sets of 40) to JLab are in the plan. Jlab mentioned that delivery at the end of April meets our timeline.
- Alam has completed the design of the main SiPM testing board in 6 layers. Presently investigating based on input from Serguei whether this can be reduced to 4 layers. This would simplify fabrication and increase options for production.
- SiPM update
- First Article testing (YI)
- Test setup is proceeding well. Control software has been completed for readout of the Flash ADC and for measuring the IV curve. Sample tests have been completed.
- The response of the SiPM amplifier board develops oscillations when many cells are plugged in. Carl and YI are working with Fernando to solve this problem.
- Expect the test setup to be ready when the First Article units arrive in about a week.
- First Article testing (YI)
- Simulations
- Electronics/cooling
- Geometry and light guides
- Monitoring system light injection: Media:athens_led_fiber.pdf
- Testing of double-ended readout. LED is glued to a scintillating fiber, which was inserted and glued into a small hole drilled into the light guide at a 15 degree angle (few mm deep).
- The fiber effectively "collimates" the light to direct it toward the far pmt. The near pmt receives reflected light.
- Ratio of Far/Near signals was determined to be 1.9.
- Multiple optimizations can still be studied. Will suggested trying an angle closer to 0 degrees. Athens has determined that the LED can be mounted on wires that provide flexibility in positioning and aiming.
- Eugene asked about placement in actual experiment. The picture on p. 2 shows the setup for a trapezoidal guide.
- Will: Have any timing measurements been completed? No to date.
- Beni inquired about the asymmetry in the ADC disctribution on p. 5. This may be due to multiple reflections and should be studied further.
- Eugene noted that if only a small fraction of the (reflected) light is visible in near pmt, it might be quite sensitive to details of geometry and or positioning.
- Zisis will summarize the work into a document for further feedback.
- Monitoring system light injection: Media:athens_led_fiber.pdf