Revision as of 13:40, 15 September 2008

Usual Time: 10:30 ET.

• 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 Sep 2 calibration meeting

1. Each subsystem must complete blanks in specification table.

Items for followup from Aug 18 meeting

1. George: report on trip to Edmonton
2. Estimates of pedestal width (electronic noise, etc.) for FM PMTs. The dark rate should be negligigle in this case.
3. Resolution studies with up-to-date geometry (Blake) ONGOING
4. Resolution studies with different segmentation for the outer section. - LOWER PRIORITY
5. Add F100 rad hard glass to simulation. - Matt will do this
6. Decision on Bcal sampling fraction needed by Sep. - Work by Stamatis (on vacation) will be summarized upon his return.

Documents to Review

1. Media:PDEgraph.pdf
2. Media:frac.pdf

Tentative Agenda

1. Announcements
2. Results on study of increased sampling in BCAL
3. Status of simulation tasks and discussion of priorities
   • Improved simulation of resolutions
     • Include realistic threshold for FM option
     • Studies of timing resolution
   • Study impact of inactive material at the end of Bcal on acceptance
     • Inactive material includes light guides, light detector, cables, dark box or cover, etc.
     • Comparison between SiPM and FM options
     • How many (which) changes in geometry should be studied?
4. Final agenda for the GlueX-Collaboration-Sept-2008

Post Discussion on SiPMs

1. SiPM: A35H vs A20H devices
2. Delivered types (all 1x1 mm are circular, all 3x3mm are square)
   • 1x1 A20H contract units were Getter 2, circular
   • 3x3 A20H contract units were Getter 1, square
   • 1x1 A35H contract units were Getter 2, circular
   • 3x3 A35H contract units were Getter 2, square
   • 3x3 A35H engineering (JLab only) units were Getter 1, square
3. Options for arrays:
   • 3x3 A20H Getter 1 or Getter 2
   • 3x3 A35H Getter 1 only

Minutes

Attending: JLab: Elton, Elke, Tim, Beni; Santa Maria: Will at CERN; UofR: Zisis, Blake, Kathryn, Stamatis

1. Results on study of increased sampling in BCAL
   • Various studies have been completed. The motivation is twofold: 1) investigate the options for reduced Bcal threshold, 2) alleviate requirements on PDE.
   • Updated understanding of the 'nominal' geometry now results in a sampling fraction of about 11.5%.
   • May need to prototype small samples to determine true amounts of lead in sandwich. The layers are becoming so small, that calculations or modeling may not be very accurate.
   • Elke: What is the leakage for each configuration? Zisis: Data available but not analyzed.
   • Will: What is the stability of sampling fraction on selection cuts? CLAS experience is that there was no natural threshold, but final simulations use 100 keV. (Will send reference to CLAS documentation). Zisis: Studies were completed last spring for Bcal NIM article, and the minimum energy will be checked.
2. Status of simulation tasks and discussion of priorities
   • Improved simulation of resolutions
     • Include realistic threshold for FM option
     • Studies of timing resolution
   • Study impact of inactive material at the end of Bcal on acceptance
     • Inactive material includes light guides, light detector, cables, dark box or cover, etc.
     • Comparison between SiPM and FM options
     • How many (which) changes in geometry should be studied?
3. Final agenda for the GlueX-Collaboration-Sept-2008

Post Discussion on SiPMs

1. SiPM: A35H vs A20H devices
2. Delivered types (all 1x1 mm are circular, all 3x3mm are square)
   • 1x1 A20H contract units were Getter 2, circular
   • 3x3 A20H contract units were Getter 1, square
   • 1x1 A35H contract units were Getter 2, circular
   • 3x3 A35H contract units were Getter 2, square
   • 3x3 A35H engineering (JLab only) units were Getter 1, square
3. Options for arrays:
   • 3x3 A20H Getter 1 or Getter 2
   • 3x3 A35H Getter 1 only