Jul 17, 2012 Calorimetry

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Teleconference Time: 11:00 a.m. EST'

  • ESNET (Number is 8542553) and EVO session (GlueX Calorimetry meeting room)
  • Phone connection only upon request.
    • +1-866-740-1260 : US+Canada
    • +1-303-248-0285 : International
    • then enter participant code: 3421244# (remember the "#").
    • or www.readytalk.com (and code without the #)

Participant Direct Lines

  • 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


Items for followup from previous meeting(s)

  1. Fcal
    • When to ship structure to JLab? (Elton and Tim to review schedule) Should be ready by mid to late August.
  2. SiPMs
    • Show distribution of response uniformity of all SiPMs compared to specifications. See today's presentation

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Monitoring
    1. LED system on Mini BCAL
  4. FCAL
    1. Construction Status
    2. 2011 Hall B FCAL Beam Test (John)
  5. BCAL
    1. Activities at JLab (Module positioning, SiPM binning, LG Travellers)
    2. Cosmics at Regina
    3. Update on BCAL Beam Tests 2012
  6. USM update
    1. SiPM Update (Javiera)
    2. Working Point Analysis (Orlando)
    3. Light guides (Iñaki)
  7. TDR update
    1. Instructions for the TDR (You must be logged into the wiki to access this page).
    2. We need to start revising Chapter 4 Detector, Section 4.3 Calorimetry.
    3. Calibration of Calorimeters
  8. Simulations/Reconstruction
  9. Any other business

Minutes

Attendees: David, Beni, Tara, Elton, Yi, John L. (Jlab); Zisis, Andrei (UofR); George, Stratos, Christina (Athens); Javiera, Orlando, Alam, Iñaki (USM); Matt (IU)

  1. Announcements
  2. Review of Action Items
  3. Monitoring
    1. LED system on Mini BCAL
      • ‎LED System, 2012 Calorimetry
      • Tara presented data using the LED monitoring system. Showed a) data of amplitude vs. LED bias voltage b) some data on cross talk c) stability data for a run over the weekend
      • Some data are still not fully digested. There appear to be some pedestal shifts that are not completely understood. Most channels show cross talk of about 1%, but one shows cross talk of up to 10% and needs investigation
      • Christina: Need to systematically understand each individual channel before evaluating the cross talk
      • Beni: Shift of light guides from one side compared to the other could lead to apparent optical cross talk
      • Andrei: Suggests that we disconnect the cables to selected LEDs and check for electronic cross talk. Zisis: add decoupling of some LEDs first to study cross talk in more detail, and then decouple the remainder to study noise pickup. Elton: We can do this once and should plan a program to do this once other tests are completed, because it won't be possible to recable the LEDs.
      • George: A signature of electronic cross talk (and capacitative coupling) might be distorted signals and/or time shifts relative to the LED pulse. Elton: We have looked at the scope for such behavior and find none.
    2. Athens (Christina)
      • George L. has delivered three SiPMs and electronics to Athens. They will hook them up to the Baby cal and complete similar studies to those done here at JLab.
      • Athens has a single power supply so will need to find a way to power three SiPMs at the same time. The Vop values should be available with the SiPMs. We also have that information in a data base at JLab.
      • Production: LEDS have arrived in Geneva; flexiboard delivery is expected for Aug 6
  4. FCAL
    1. Frame
      • Construction is progressing smoothly
      • John F. is fitting Al pieces into the steel frame. Some workarounds have been required but possible. Could ship the frame in about a month. Will ship frame independent of other items. Need to check logistics and schedule with Tom Carstens.
      • Tim: The platform should be assembled by mid Aug and we can receive the frame.
    2. Bases
      • Have 1500 bases fully assembled and tested. Waiting on more socket boards (1300 still needed). Have several hundred multiplier boards waiting.
      • Overnight burn-in tests sees a 1-2% failure rate. Paul is not surprised and attributes failures to infant mortality of caps. No large systematics seen. These few failed bases will be set aside for later diagnostic and fixes. This is well within the fabricated spare capacity.
    3. Dark room
      • John F. is starting a layout of the dark box on the platform and finds there is little space for it. Work will continue on the layout and will need feedback from Tim and Tom.
    4. Cable labels
      • Waiting on Fernando to approve the labeling scheme. Labeler and student are waiting for the word to start.
    5. Students
      • Two students will come to JLab in a couple of weeks to assist on assembly of the Fcal. One needs a JLab sponsor, and desks have been coordinated through the User's Office.
      • Schedule for installation is being outlined. Soon will request feedback from Tim and Tom.
    6. 2011 Hall B FCAL Beam Test (John)
  5. BCAL
    1. Activities at JLab (Module positioning, SiPM binning, LG Travellers)
      • Shaun Krueger is developing a plan to bin the SiPMs into groups of 40 for assignment to sides of Bcal modules.
      • Tegan Beattie is working on the layout of the modules inside the craddle
    2. Cosmics at Regina
      • Measurements have been taken at 2 different bias voltages
      • The plan is to add an amplifier and study timing
    3. Update on BCAL Beam Tests 2012
      • No progress. However, the plan is to revisit the data, especially the timing, and complete an analysis and writeup in August.
  6. USM update
    1. SiPM Update (Javiera)
      • Plan to ship 600 units to JLab next week
      • Next to last shipment of SiPMs (640 units) from Hamamatsu are in customs in Santiago
    2. Working Point Analysis (Orlando)
      • Orlando updated his talk from last week, correcting the data on cross talk. Showed a plot of cross talk increasing with bias voltage, essentially independent of temperature
      • Updated summary plots of all quantities, separated out for different temperature settings.
    3. Light guides (Iñaki)
      • Presented a table listing status of all light guides
      • Part on milling machine has been replaced. Machine is being calibrated with each new light guide
      • Expect to start machining on Thursday
  7. TDR update
    1. Instructions for the TDR (You must be logged into the wiki to access this page).
    2. We need to start revising Chapter 4 Detector, Section 4.3 Calorimetry.
      • Zisis has started working on the TDR. The plan is to check in an initial version of text without figures. Elton will review and after iteration, an initial draft will be made more widely available
      • Zisis and Christina will work together to draft a section for the monitoring system
      • A section on mechanical assembly/installation will also be needed and we will work with Tim to draft a section
      • The section on SiPMs will be drafted initially at JLab and added to the chapter
    3. Calibration of Calorimeters
  8. Simulations/Reconstruction
    • BCAL Simulation Status Update (David)
    • David went over quickly some recent results of his simulation. More time will be devoted at a later time for presentation and discussion.
  9. Any other business