May 27, 2010 Calorimetry

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Teleconference Time: 11:00 a.m. EDT

  • ESNET and EVO session
  • Phone in CC F326 is 757-269-6337
  • Phone in the Regina Videoconference Suite is 306-585-4204
  • Phone only if requested:
    • +1-800-377-8846 : US
    • +1-888-276-7715 : Canada
    • +1-302-709-8424 : International
    • then enter participant code: 77438230# (remember the "#"). Phone line by request only.

Items for followup from previous meeting(s)

  1. Monitoring
    • Bcal: Testing to see if LED sources can be viewed by pmts on both sides of the module (UofR/UofA).
  2. Fcal
    • Draft agenda for Readiness Review (Elton and Matt)
    • Decision on rad hard detectors
  3. Bcal
    • Send copy of contract with Ross to JLab
    • Report on beam test data at small incidence angles. Ongoing work.

Discussion of Options for Radiation-Hard Insert

Options for Radiation-Hard Insert

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Calibration/Monitoring (Zisis)
  4. FCAL
    1. Construction status
    2. FCAL Fabrication Readiness Review
    3. To shashlyk or not to shashlyk. Options (Elton) see Table. Physics Impact, see GlueX-doc-1481
    4. PbWO Insertion. (Ashot) . see [1]
  5. BCAL
    1. Calorimeter input to PAC (Zisis)
    2. Construction Status
    3. Lead: 6th order of 13cm-wide sheets
    4. Fibres: Media:FibresAttenLenShips1-12.png
    5. Npe corrected numbers: Media:ZoomedPage31.png and Media:ZoomedPage38.png
    6. USM MPPC test stand design update
  6. Simulations
  7. Other Updates


Attendees:Elton, Tim, Beni, Fernando, Eugene, Pedro, Ashot, Liping,Ilya Larin (JLab); Matt, Ryan (IU); Zisis, Andrei (UofR); Will, Sergey, Alam (USM).

  1. Announcements
    • EVO connection problems, used phone
    • USM MOU has been finalized. Document will be sent to Will to start collecting signatures.
  2. Review of Action Items
    • Athens has received two Winston Cones for testing of calibration sources.
    • Stamatis is working on this data as part of his master's thesis. Will report soon on results.
  3. Calibration/Monitoring (Zisis, George)
    • Athens has confirmed data from UofR regarding the large differences in light seen by opposite pmts.
    • Options for calibration procedure include a) adjusting HVs depending on which side is to be calibrated b) Turning one side off and adjusting light output to the other side.
    • Elton: Use of trapezoid light guides might allow for more flexibility in placing LEDs.
    • USM is producing some trapezoidal light guides, but cannot yet polish them.
    • USM promised to send (unpolished) 4 guides to UofR and 2 guides to Athens. Will take a couple of weeks.
    • Fernando: Drivers could be incorporated on the back of the amplifier boards, but communication should use either RS232 or RS245 to allow for about 50 ft range.
  4. FCAL
    1. Construction status
      • New tech, Steve, started 3 weeks ago. Waiting for parts (face plates and jack plates) to start work. Delay due to getting purchase out. Company is now starting to produce pieces, which can be delivered in smal batches to allow assembly work to proceed.
    2. Electronic bases
      • 3 out of 4 boards working just fine.
      • Problem with multiplier board. Sparking causing failures. Problem traced to spacing between components. Potting the board with epoxy fixed problem.
      • Plan is to make another layout of the board with increased spacing, and try to avoid potting. If potting is unavoidable, will only pot with epoxy sensitive areas for access to most of the components on the board.
      • Shipped 16 Fcal cables to Fernando for evaluation of fire rating.
      • Plan to send the Fcal time NIM article out tomorrow.
    3. FCAL Fabrication Readiness Review
      • Confirmed June 23-24 as dates for Readiness Review
      • Electronics review will be delayed till new layout is complete and under test. This will likely be 30-45 days.
  5. BCAL
    1. Calorimeter input to PAC (Zisis)
      • George and Zisis have summarized progress on the BCAL since the last PAC. Zisis also uploaded GlueX-doc-1536 with up-to-date information on the Bcal.
    2. Construction Status
      • Modules 9 and 10 builds are complete. With lights off, a straight edge can be seen through the un-machined modules. Look good!
      • Main machined at Ross has been down several weeks, delaying start of modules 5-8. They have now resumed operation.
    3. Lead: 6th order of 13cm-wide sheets
      • Approval of additional purchase of lead sheets will allow overall increased efficiency and speed of operation.
    4. Fibres: Media:FibresAttenLenShips1-12.png
      • Zisis will pass this information on to Kuraray for comments on any discrepancies between UofR and Kuraray measurements for shipments 10 and 11. Npe measurements are behind due to disruptions in lab space availability. They are starting back up.
    5. Npe corrected numbers: Media:ZoomedPage31.png and Media:ZoomedPage38.png
    6. USM MPPC test stand design update
  6. Simulations
Elton and Fernando:

I corrected the dynamic range of BCAL according to Irina's results (from
gluex-doc-1474 note). The attachment contains "zoomed" plots from the note
pages 31 and 38 (for easy reading of the spectra edges).

Please use the corrected numbers for your references in the future.

Thank you,

All Data from GlueX-doc-1474

         Shower                Upstream  Fig   Downstream  Fig
Eg (GeV)  Theta    Phi    Sum      Npe           Npe
0.06       105     gap   Inner-3   120     30     50         31(zoom)
0.06       105     gap   Inner-1    90     38     40         38(zoom)
2.5         12    center Inner-3  7500     15   17000        14
2.5         12    center Inner-1  5500     34   13000        33

Ratio (dynamic range)             62.5            340
                                   61            325
  1. Discussion of Fcal Insert
    1. To shashlyk or not to shashlyk. Options (Elton) see Table. Physics Impact, see GlueX-doc-1481
    2. PbWO Insertion. (Ashot). See [2]
    3. Substantial discussion on this topic. Generally, Elton and Ashot's numbers are starting to converge and differences are being identified. Fiducial region different between the calculation.
    4. Mechanical issues for PbWO4 solution include
      • Magnetic shielding for small 20mm Hamamatsu tubes. In PRIMEX, exposure to Bfield as about 10-20 G. Shielding of entire area might be the optimal, although shields for Fcal tubes might contribute to difficulty in this case.
      • Mechanical pressures on crystals. For PRIMEX about 6 blocks stacked on crystals. For Hall D will stack about 20.
    5. Small segmentation of calorimeter has advantages beyond simple position resolution, as it helps avoid pileup and allows resolving showers at closer distances.
    6. Ashot's simulation uses a 20x20 cm2 fiducial volume beam hole. This means 3x3 blocks +1 block on either side for containment.
    7. Elton and Ashot will try to resolve any discrepancies offline.
  2. Other Updates