July 30, 2013 Calorimetry

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

• ESNET (Number is 8542553) and EVO session (GlueX Calorimetry meeting room)
  • Software for connecting to ESNet
• Phone connection only upon request.
  • +1-866-740-1260 : US+Canada
  • +1-303-248-0285 : International
  • then enter participant code: 3421244# (remember the "#").
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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. Transmission: Report back on more transmission measurements (Shaun and Elton)
2. FCAL cover during solenoid tests (Elton and John)

Tentative Agenda

1. Announcements
2. Action Items
3. Monitoring
   • FCAL Concept for FCAL Monitoring Plane
4. BCAL
   1. SiPMs Update
      • Three units (SN: 80 JLab, 219 JLab, 1933 USM) were found to be "hazy" during installation onto the readout assemblies at JLab.
      • We have original photos from unit at USM after some cleaning. No degradation in performance was observed
      • Media:SiPMHaze1.JPG SiPM 1933 with "haze" at USM after cleaning
      • Media:SiPMHaze3 atJLab.jpg SiPM 1933 with "haze" at JLab during assembly
      • Media:SiPMHaze2.jpg SiPM 1933 with "haze" at JLab during assembly (zoom)
      • Likely the epoxy covering the sensor has been affected during handling. Carl is retesting them. Will keep these as spares.
5. Reconstruction and Simulation
   1. Electrons from J/psi
6. TDR update
7. Calibration of Calorimeters
8. Any other business
   • Elton will be away next Tuesday. Zisis will run the meeting.

Minutes

Attendees:John, Elton, Zach, George, David, Serguei (JLab); Christina (Athens); Shaun, Andrei (UofR); Will, Alam, Elias (USM); Matt (IU); Sean Dobbs (NW).

1. Announcements
   • Solenoid is cold, testing expected in the next few days
2. Action Items
3. Monitoring
   • FCAL Concept for FCAL Monitoring Plane
   • Discussion on the latest modifications to the monitoring plane. Eljen can provide UVT material for panes and also do the machining.
   • Modifications were discussed and approved by the group. JLab will proceed with ordering the panes.
4. FCAL
   • Cabling is half complete. Last pieces of the labyrinth are being machined at IU. Expect delivery in a couple of weeks. Cabling of upper section must wait on these pieces
   • The environmental monitoring system is making progress. All pieces are made and tested
   • Boxes are being fabricated and buttons being prepared. Expect a fully assembled system in a week.
   • PLC connections will be made once Dave Butler is freed up from his solenoid duties.
   • Elton: IU contract will be completed in August. It seems everything is on track for it to be completed.
5. BCAL
   1. Contract
      • Danny is returning to decommission the module factory in August and the contract will be completed.
   2. SiPMs Update
      • Three units (SN: 80 JLab, 219 JLab, 1933 USM) were found to be "hazy" during installation onto the readout assemblies at JLab.
      • We have original photos from unit at USM after some cleaning. No degradation in performance was observed
      • Media:SiPMHaze1.JPG SiPM 1933 with "haze" at USM after cleaning
      • Media:SiPMHaze3 atJLab.jpg SiPM 1933 with "haze" at JLab during assembly
      • Media:SiPMHaze2.jpg SiPM 1933 with "haze" at JLab during assembly (zoom)
      • SN 1933 was tested several times, including once again before shipping to JLab (about six months after cleaning). No significant degradation in performance was observed relative to other sensors.
      • Likely the epoxy covering the sensor has been affected during handling. Carl is retesting them. Will keep these as spares.
      • Alam: The unit was cleaned with alcohol (isopropyl?) creating this haze. Since then any cleaning has been performed using distilled water.
      • Elton: After Carls tests, if they continue to show no change in performance, we replace them with newer units and will keep them as spares.
   3. Testing at Regina
      • Temperature dependence of SiPM performance continues.
      • Shaun has been away since he was at JLab and will return to working on the cosmic ray data.
6. Reconstruction and Simulation (Sean Dobbs)
   • Electrons from J/psi
   • Sean showed slides with expected energy distributions of electrons from J/Psi decay. Energies range from 0 to 6-7 GeV.
   • There have been some discussions of consequences of overflow.
   • The ADC overflows at 4096 (12 bits). The pulse sum has more bits, but it is unclear from the present MC when individual samples overflow.
   • Serguei: There is also intrinsic non-linearity in the MPPC sensors, which must be corrected even before saturation occurs.
   • Matt: One may be able to use the capabilities of the Flash to compensate for saturated pulses by fitting to the pulse shape.
   • David: Discussions on the data format for the Flash-125 are converging on a scheme that combines the sum and timing information with the slot/channel information into two words. This allows for additional bits to be used for quality factors including information about saturation. After the discussion of the Flash-125 is settled, we may wish to revisit the format for the Flash-250 and incorporate some of their ideas.
7. TDR update
8. Calibration of Calorimeters
9. Any other business