Feb 12, 2013 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 757-269-6460 (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. After summary of SiPM parameters, provide data to Hamamatsu for comments (USM)
  2. Fcal: JLab to provide feedback (approval) on dark box construction (Tim and Chuck)

Tentative Agenda

  1. Announcements
  2. Collaboration Meeting
  3. Action Items
  4. Monitoring: Media:UpdateFCALFeb2013_2.pdf
  5. FCAL - 1080 Blocks Stacked [1]
  6. BCAL
    • Tested modules 45, 48, 49, 46, 47, 44, 42, 41
    • Media:Run638 cosmic fadc Mod41.pdf Overnight cosmic-ray run for module 41
    • Trigger provided by single 30x10cm2 counter placed underneath the middle of the module
    • Data is pedestal subtracted. Pedestal sigma ~ 1 count
    • Peak is at 18 counts. Expect mip ~ 20 MeV ~ 20 counts.
  7. USM
  8. Simulations
    • Wrapping up loose ends on BCAL simulation
    • Plan for BCAL reconstruction
    • Hadron interactions in FCAL
  9. TDR update
  10. Calibration of Calorimeters
  11. Any other business

Minutes

Attending: Elton, Yi, Beni, David, Eugene, Sasha (JLab); Christina, Pavlos, Stratos (Athens); Matt (IU); Zisis, Shaun, Andrei (UofR); Hayk, Alam, Elias, Will (USM).

  1. Announcements
    • Regina crew will participate in the Winter/Nuclear conference in Banff, Alberta next week.
  2. Collaboration Meeting
  3. Action Items
  4. Monitoring: Media:UpdateFCALFeb2013_2.pdf (Stratos)
    • New results on slide 8
    • Configurations studied: a) blasted (i.e. sanded down with sander and #2000 sand paper, b) same but larger area blasted, c) sanded and wet with glycerine to smooth surface.
    • Beni: Blasted side near or opposite pmt? Near side, but other side shows similar results
    • By collaboration meeting will try to attain better uniformity.
    • Matt: How to relate "small" pmt response with lead glass? Compare slides 3 and 8
    • Eugene: What about regular scratches? Stratos: Have considered CNC machine to control "scratching" but none readily available.
    • Matt: In priority list for Fcal: a) cover range of required light b) stability and c) uniformity
    • Matt: please send bar code for pmt (to compare to typical sensitivity).
    • Elton: How long to complete project once acceptance is completed? Most parts are available, so fabrication should take about one month.
    • Christine: Signal measured over a 3-4 days was stable.
  5. FCAL - 1080 Blocks Stacked [2]
    • Current progress on stacking shown in picture. Already up off the step plate.
    • John Frye will travel to JLab this week or next to help set the steel for the beamhole, which floats in z
    • Survey will be done to check height of top plates and align beam hole
    • Cockcroft-Walton bases continue at steady pace toward 3000 of contract. Currently have about 100 spares
    • Dark room work continues with discussions with Chuck and Tim. Certified welds must be done correctly and according to code.
    • At some point, the stacking progres should be entered into the project schedule because it is going much faster than anticipated.
    • Will: Survey should be conducted to check for any tilting or other deflections after weight of blocks has been added. There could be changes in position, for example, due to settling of the building
  6. BCAL
    • Proposal to distribute LED bias using "rotated" quadrants, i.e. one top, one bottom and two horizontal.
    • We are using the convention that the side with the stamp identifiers will be the upstream end.
    • Tested modules 45, 48, 49, 46, 47, 44, 42, 41
    • Media:Run638 cosmic fadc Mod41.pdf Overnight cosmic-ray run for module 41
    • Trigger provided by single 30x10cm2 counter placed underneath the middle of the module
    • Data is pedestal subtracted. Pedestal sigma ~ 1 count
    • Peak is at 18 counts. Expect mip ~ 20 MeV ~ 20 counts.
    • Zisis: Suggestion to use two counters to trigger and better define cosmic-ray geometry
    • Beni: Low pedestal peak is probably offset from zero because the maximum count is taken
  7. USM
    • Orlando's poster File:OrlandoPosterViena.pdf
    • Scratched MPPC's PDE MEDIA:ScratchedMPPCsPDE.gif
    • Picked PDE to check effect of scratch damage because it seemed to be the most sensitive parameter. Other quantities were also compared but did not show any systematic differences before and after
    • PDE is relative measurement in station 3
    • Recent measurements (after scratching) are within uncertainties although somewhat higher than before (before scratching). All measurements exceed our specifications
    • Elton: Proceed with incorporating these back into the general mix of tested SiPMs. However, the complete set of sensors that are suspect should be checked.
  8. Simulations
    1. Wrapping up loose ends on BCAL simulation
      • Need to produce table with calculated constants and check the result of the GlueX simulation
      • Andrei wanted to smooth the constant list before sending them, but the accuracy smoothing has not been decided. Elton suggested that the variations in the smoothing should be compared to the induced statistical widths.
      • Andrei proposal: Send constants as they are to David to get feedback. Agreed.
    2. Plan for BCAL reconstruction
      • Meeting with David to discuss location of code and present status. Do not yet fully understand the level of problems.
      • Simulation of time resolution still needs to be resolved.
      • Elton: Reminder that the main issue in reconstruction has been that the number of clusters is (much) larger than number of photons, so pi0 reconstruction has not been possible.
      • Eugene: Should consider the optimum method to reconstruct clusters. For example, for low multiplicities, a good method is to start with large clusters and only split them up at a later time.
      • Will: Hall B cluster selection had a parameter corresponding to missing strips on each edge to differentiate clusters. A similar approach could be made for Hall D.
    3. Hadron interactions in FCAL
      • Alex: Has check whether the response of the lead glass to charged hadrons, but it has not. It is worth reviving the Fcal prototype and use it to measure cosmic rays for normalization.
      • Simulation of charged hadrons traversing a block and collecting the Cerenkov photons could be a useful exercise for a student, which can be compared to the measurements.
      • Efforts in this direction should be coordinated with IU.
  9. TDR update
  10. Calibration of Calorimeters
  11. Any other business

Attendees: