Nov 20, 2012 Calorimetry

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. Monitoring
   • Circulate for comments a concept for distributing monitoring inputs to the control boards (Elton) See e-mail
2. Simulation
   • Add up-to-date geometry for plexiglass pane and TOF detector and rerun simulation to check photon reconstruction (Elton to see if Beni or Richard can add the geometry) Beni has agreed to do this.

Tentative Agenda

1. Announcements
2. Review of Action Items
3. Monitoring (e-mail from Christina)
   • I am out of town today and cannot participate but I can report the following:
   • The plexiglas FCAL measurements came to the conclusion that the main irregularities are due to the two surfaces which are opposite the the LED's (the ones which would be touching the other quadrants) and were not polished. It seems the diffused light there close to the surface is up to 5 times more than everywhere else. So next comes the polishing of those sides and re-measurement but our technician is on strike, so we have to wait.
   • Otherwise sorting of BCAL LED's goes on and the BCAL bare Control Boards have arrived in Gva as well.
4. FCAL
5. USM update
6. BCAL
   • Radiation exposure to SiPMs during Hall B beamtest (Ivan)
7. Simulations
8. TDR update
9. Calibration of Calorimeters
10. Any other business

Minutes

Attendees: Matt (IU); Tim, Elton (JLab); Zisis, Shaun (UofR); Will, Orlando, Hayk, Feranando, Alam (USM).

1. Announcements
   • Contracts for Fcal and Bcal have been extended.
2. Review of Action Items
3. Monitoring (e-mail from Christina)
   • I am out of town today and cannot participate but I can report the following:
   • The plexiglas FCAL measurements came to the conclusion that the main irregularities are due to the two surfaces which are opposite the the LED's (the ones which would be touching the other quadrants) and were not polished. It seems the diffused light there close to the surface is up to 5 times more than everywhere else. So next comes the polishing of those sides and re-measurement but our technician is on strike, so we have to wait.
   • Otherwise sorting of BCAL LED's goes on and the BCAL bare Control Boards have arrived in Gva as well.
   • George and Stratos connected later. They indicated that the measurements on the Fcal should be completed within the next week and they could report the findings at the next Cal Working group meeting.
4. FCAL
   1. Cockcroft-Walton bases
      • Received all remaining fabricated parts. Have everything in house to complete fabrication. Should have about 2600 units already.
      • Most common failure is a transistor that fails after burn-in, but at a low rate. Do not anticipate long-term problems.
      • Waiting for the company to return extra (unused) parts in order to close out the contract.
   2. Frame
      • John is finishing metal skin around the box tubes
      • Next is the front side Al channel to hold the plexiglass sheet.
      • Building according to drawings, although simulations have not been completed. If simulations indicates a problem, the parts can be refitted.
      • The frame should be ready to ship next week. (However this may be delayed as John has been called in for jury duty)
      • Matt suggests that the assembly may be easier on the floor for better access. We need to consider this when the frame to unload the frame where it is most useful
      • Zisis: Do you anticipate challenges with shimming/leveling? Matt: Believe to have anticipated the main issues. Frame will be aligned by JLab. Insert pieces are aligned to the frame and should fit back in smoothly. The beam tube was built by the shop with deviations of less than about 15 mils, well within spec.
      • Waiting on Tim to provide feedback on dark room frame drawings.
   3. Cables
      • Finished labeling and bundling cables at IU
      • Elton should check about the status of the cables ordered by JLab
5. USM update
   1. SiPMs
      • Last shipment from Hamamatsu included commercial invoices that should have been omitted. The tax implications are large ($50k) if a workaround cannot be found. Expect resolution in the next few days.
      • Elton: Hamamatsu has provided the data from the 10 extra SiPMs. This completes the information needed to setup the jumper sheets for Bcal readout boards.
      • The latest up-to-date plots of SiPM measurements compared to specifications has not been sent. Orlarndo will provide the latest at 1.2 V above breakdown for feedback from Elton.
   2. Light Guides
      • New box with 400 units will be shipped out today. That will make 1440 shipped to JLab. Expect the next box to be shipped in about a week.
      • Elton inquired about the measurements that showed some outliers. Hayk
6. BCAL
   • Radiation exposure to SiPMs during Hall B beamtest (Ivan)
7. Simulations
8. TDR update
9. Calibration of Calorimeters
10. Any other business