Aug 18, 2008 Calorimetry

Connection

• The meeting will be held at 10:30 am ET
• Phone:
  • +1-800-377-8846 : US
  • +1-888-276-7715 : Canada
  • +1-302-709-8424 : International
  • then enter participant code: 39527048# (remember the "#")

Reference Documents

1. Previous minutes: July 21, 2008 Calorimetry
2. Schedule, Tracker and Drawings (gluex pass)

To-do List from previous meeting

1. Identify files with new geometry (Beni)
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)
4. Resolution studies with different segmentation for the outer section.
5. Add F100 rad hard glass to simulation.
6. Calibration meeting Tues Aug 26
7. Decision on Bcal sampling fraction needed by Sep.

Agenda

1. Announcements
   • Calibration meeting scheduled for Tuesday Aug 26. Are we on track for this?
2. Discussion
   • Preparation for construction procurements in FY09
   • Geometry and drawings - sign off procedures
   • Schedule for evaluation of bid responses to fiber RFP.
   • Discussion on agenda Items for collaboration meeting
3. Reports
   • Geometry for simulations in repository (Beni)
   • Updates on simulation of performance (Blake)
     • energy resolution with and without Aluminum plate:
       • 
   • Toy model for bcal timing (Elton)
   • Preparations for construction (George and Jim)
   • Specifications for Lead procurement (Elton and George)
   • Measurements of fiber light output (Andrei)
     • Preparations for fiber testing at JLab (Beni)
4. Review of To-do List
5. Updates
   • Calibration system
   • FCAL
   • BCAL
6. Any other business

Minutes

Attending:UofR: Andrei, George, Blake; JLab: Tim, Elton, Beni, Elke; Athens: Chistine; IU: Matt

1. Announcements
   • The next calorimeter working group will be devoted to Calibration on Tuesday Sep 2.
2. Discussion
   • Preparation for construction procurements in FY09
     • Bcal - fibers, lead, glue, ...
     • Fcal - replacement pmts, Cockcroft-Walton Bases, updates for PbWO2 blocks -- need resolution with PRIMEX by collab meeting, rad hard glass
   • Geometry and drawings - sign off procedures
     • all major drawings will require signature from collaborating instituion
     • The proposal is to have a signature page with a drawing list, to be completed and faxed between institution and JLab.
     • Signatures of appropriate experts can be added as needed, for example Jan Soukup might sign off on Bcal drawings.
   • Schedule for evaluation of bid responses to fiber RFP.
     • Bid responses expected today. Technical evaluation team will review bids when they arrive.
   • Discussion on agenda Items for collaboration meeting
     • Bcal: Update on simulation results (Blake?)
     • Bcal: Update on SiPM measurements and alternative readout (?)
     • Fcal: timing resolution and mechanical stacking and assembly (Mijahlo? Matt?)
     • FM pmts: Werner has made some measurements of the FM pmts in the Big Bite magnetic field. (Report perhaps under start counter).
     • Discussion on beam tests (perhaps together with chamber tests)
3. Reports
   • Geometry for simulations in repository (Beni)
     • Geometries placed in a studies area svn repository.
     • Light guides for 3x3 configuration added. Light guides are 50 cm upstream. Beni remembered will check) that the pmts are modeled as 2x2x2 cm3 Al blocks, same as SiPMs. Al plate has also been
     • Beni to check that there is no interference with FDC cables (in software).
     • PbW02 geometry has also been incorporated into the software including factories to get data. However, cluster finding/analysis is still needed. Matt thoguth that their cluster-finding algorithm could be easily adapted, although thresholds and calibrations would need to be adjusted. PRIMEX should take on this project and communicate with Matt and Beni with questions.
   • Updates on simulation of performance (Blake)
     • Blake showed a comparison of simulations with/without the Al plate. No change in energy resolution. (At the lowest energy, the Al plate shows a slight improvement which Blake attribues to fitting systematics). Position resolutions have not been checked.
     • energy resolution with and without Aluminum plate:
       • 
   • Toy model for bcal timing (Elton)
     • Elton showed the results of a toy model for evaluating the effect of segmentation on the timing resolution. Only a constant term becomes smaller as segmentation increases. If thresholds are included, systematics tend to degrade the timing resolution.
   • Preparations for construction (George and Jim)
     • George is flying to Edmonton tomorrow to plan for construction activities, especially evaluate space requirements for swagging and cutting Pb.
   • Specifications for Lead procurement (Elton and George)
     • Elton is collecting specifications for the Pb and there is a preliminary specification document in preparation.
   • Measurements of fiber light output (Andrei)
     • Trying to reporduce fiber light output measurements with a calibrated pmt from Hamamatsu
     • Two Hamamatsu pmts were calibrated by Hamamatsu, including QE, radiant flux, and gain. However pmt divider used needs to be clarified.
   • Preparations for fiber testing at JLab (Beni)
     • Beni is waiting for materials for final test setup
     • In the interim, a makeshift dark box has been constructed a setup with an XP2020 viewing a LED and a Sr. source has been setup. A clear single p.e. peak for the XP2020 pmt is obtained when the LED is triggered at 10 times the rate for XP2020 signals (indicating that the incident light is less than one p.e. on average). To see the single p.e. peak amplification of x10 is required in addition to running the tube at a relatively high setting for the high voltage. A comparison of the Sr. source and the single p.e. peak should yield the number of p.e. per fiber.
4. Review of To-do List from previous meeting.
   • Identify files with new geometry (Beni) - DONE.
   • Estimates of pedestal width (electronic noise, etc.) for FM PMTs. The dark rate should be negligigle in this case.
   • Resolution studies with up-to-date geometry (Blake) ONGOING
   • Resolution studies with different segmentation for the outer section. - LOWER PRIORITY
   • Add F100 rad hard glass to simulation. - Matt will do this
   • Calibration meeting Tues Aug 26 - changed to Sep 2
   • Decision on Bcal sampling fraction needed by Sep. - Work by Stamatis (on vacation) will be summarized upon his return.
5. Updates
   • Calibration system
     • Filters received have been checked between few % and 50% and are operating properly. Testing of diffusers is still ongoing.
   • FCAL
     • Work has slowed at the end of the summer. John continues to work on the support structure for the full prototype using components from previous projects.
   • BCAL
6. Any other business

Items for followup:

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.