Apr 16, 2009 Calorimetry

Teleconference Time: 11:00 a.m. EST

• Phone:
  • +1-800-377-8846 : US
  • +1-888-276-7715 : Canada
  • +1-302-709-8424 : International
  • then enter participant code: 39527048# (remember the "#")

Items for followup from previous meeting(s)

1. Resolution studies (Blake)
   • Develop criteria for evaluating resolution studies
   • Study impact of inactive material at the end of BCAL on acceptance.
   • Check what configuration (thresholds, step sizes, stack? parameters for secondaries, etc) is being used for the Hall D simulations (Regina)
2. Review options for import/export to Chile (loans, donations, transfers, etc.)
3. Bfield calculations for new FCAL mag shield design to evaluate impact on pmt performance.

Tentative Agenda

1. Announcements
2. Calibration (Athens)
   • LED layout
3. FCAL Update
4. Simulations
5. BCAL Update
   1. Preparations for construction
   2. Cooling of BCAL Readout
      • Sensitivity to voltage temperature (Elton)
   3. Update on Hamamatsu and Sensl Sipms PPT: [1] (Carl)
6. Agenda Collab. Meeting [2]
7. Review of Action Items

Minutes

1. Attending: JLab: Elton, Beni, Carl, Eugene, Fernando, Tim; UofR; Zisis, Andrei; IU: Matt, Ryuan, Mihajlo, Claire; USM: Will.
2. Calibration (Athens)
   • LED layout
   • Athens has prepared a new circuit board which now fits into the existing BCAL geometry with Winston cones. Could move the LED off the board if more room is requried.
   • Eugene: It is difficult to make a small pulses with LEDs. Zisis mentioned that there will be tests at Regina to investigate optimal configuration of such a system, including neutral density filters, installation to illuminate the far pmt, and experiment with setups that allow near and far pmts to see the LED light.
   • Eugene: One should also shield the SiPM amplifiers from the LED pulsing mechanisms.
   • Christine will attend one of the next two collaboration meetings, might give a report in May.
3. FCAL Update
   • MOU in circulation. We have received feedback from Allison. Will discuss comments following this meeting.
   • Hardware tests of assembly individual module [older design] is underway. Building a pulsed LED to monitor gain, including response of pmt base. Paul Smith is interested and helping.
   • By summer/fall will have five operational assemblies of new pmt base assembly design.
   • Still need final magnetic fields inside new shield assembly. Tim: Bill has studied new ANSIS calculations of B-fields with new shield. Using a 0.5 mm gap and mu-metal they get a residual field of 1.7 G. Tim will make plots of Bfield as a function of position.
   • Working with company to produce a phosphate (?) anti-corrosion coating. Initial outdoor test is surviving without corrosion.
   • Looking for vendors of F-108 rad hard glass. Vendor is promising 50micron tolerances on transverse dimensions (which should be ok). Will need polishing.
   • Data sheet is available, and Matt will post either to wiki or to portal.
   • Electron storage ring now available at IU. Currently delivers 6 or 26 MeV. Goal is to increase energy to 100-200 MeV. Working with group on possibility to use this device to irradiate Pb glass and investigate rad damage in some detail. This will help studies of the effects of transparency on resolution.
4. Simulations
   • No update. Reconstruction meetings will resume on Tuesdays at 11:00 am, and Blake will return focus on reconstruction.
5. BCAL Update
   1. Preparations for construction
      • Elton: RFQ for fixed-price construction prototype procurement should go out soon. Award can be made quickly as soon as UofR responds. Contract for production is in the works and we hope will be awarded by mid summer.
      • Zisis:
      • Start operation May 1 with five students, and start swaging on May 18 using existing lead.
      • Bids for production quantities of lead should come in this week. Expect samples of all sizes in June, with quantities for one module in July. Full quantities will be delivered in four large shipments over the next year.
      • Waiting on production schedule for fiber delivery. Expect first shipments in early May.
      • Sending requests to Bicron and Eljen for purchases of epoxy.
      • Expect to complete production prototype in early September. Schedule calls for first four modules to be completed by Feb 2010.
   2. Cooling of BCAL Readout
      • Sensitivity to voltage temperature (Elton)
      • Elton added section on sensitivity of SiPMs to voltage and temperature to existing GlueX-doc. Will suggested a table be added with a list of sensitivities to voltage.
   3. Update on Hamamatsu and Sensl Sipms PPT: [3] (Carl)
6. Agenda Collab. Meeting [4]
7. Review of Action Items