Revision as of 13:52, 27 October 2008

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Items for followup from Oct 13 meeting

1. Each subsystem must complete blanks in the Calibration Specification Table.
2. Updated schedule with new Fcal procurement dates. (Elke will send this to Matt)
3. Tests of Fcal magnetic shields (Tim and student).
4. Decision on Bcal sampling fraction needed if any changes are to be made to design.
5. Resolution studies (Blake)
   • Develop criteria for evaluating resolution studies
   • Up-to-date geometry ONGOING.
   • Decreased threshold for FM pmts. ONGOING
   • Position resolution - understand dependence on granularity.
   • Different segmentation for the outer section. - LOWER PRIORITY
6. Study impact of inactive material at the end of Bcal on acceptance.
7. Add F100 rad hard glass to simulation. - New graduate student has been assigned this project.
8. Add roadmap for Bcal Roadmap to wiki (Elton)

Documents to Review

(W. Brooks) Some time ago I promised to provide a study performed by Etienne Burtin in 1995 of the CLAS forward calorimeter performance, particularly, the sensitivity of the sampling fraction to the GEANT cutoff. It turned out that there was no software copy known to be available, but a hardware copy resided in the author's office; he kindly photocopied it, and hand-carried it to CERN for me, and I scanned it in. Figure 3.7b is the plot of interest, in scanned page 10 or the document's page 59.

It's too big to download into the wiki, so I linked it from here:

http://www.jlab.org/~brooksw/burtin_thesis.pdf (~6 Mbytes)

Tentative Agenda

1. Announcements
2. Calibration
   • Progress on filling in the Calibration Specification Table.
3. Fcal
4. Bcal
   • Decision on use of Getter#1 and no Getter units in the construction of arrays. Discussion
     • Summary of delivered units
     • Original plan was all Getter#1 devices. Sensl now proposes a 50/50 split, Elke has proposed 80/20 plit.
   • Decision on lead thickness
     • Updates on sampling studies (Stamatis) Media:Meeting271008.pdf
     • Comments by Will Brooks on Hall B thesis (see above).
     • What is the gain? What needs to be tested if a change is desired?
   • Roadmap toward a decision for the Bcal readout
     • Comments on APD's (Serguei)
   • Updates on resolution studies (Blake)
     • have simulated pi0s in both geometries, have had compiling issues with analysis code the last week
   • Visit to Alberta
     • Schedule a phone conference for followup

Minutes

Attending: UofR: George, Andrei, Zisis, Blake, Stamatis; IU: Matt, Claire, Brad (studying radiation on blocks); JLab: Beni, Tim, Elton, Elke; TSM: Will

1. Calibration
   • Filling Calibration Specification Table.
     • Zisis and George have added entries to the table.
     • IU meet internally and is discussing best numbers for table. Claire is studying how to calibrate the Fcal using pi0's. Based on results this will have an impact on the frequency and accuracy needed of a monitoring system
     • The requirements should be reviewed in a future meeting when all input is presented so that an informed decision can be made as to whether a single or multiple monitoring systems are required for the scintillating detector systems.
2. Fcal
   • Progress on timing studies - Jake will report at the next meeting
   • Tim: Update on 64-block prototype? John has talked to local machine shops and has been reviewing specifications and schedules.
   • A detailed schedule for construction is being generated with FASTTRACK. Elke will send updated schedule with new procurement dates (which have been changed).
   • Matt inquired about the status of the magnetic shield sent to JLab. Tim' student will test in magnet, but will take a month or two. Matt's main interest is in feedback about steel specifications in shield and thickness requirement.
3. Bcal
   1. Decision on use of Getter#1 and no Getter units in the construction of arrays. Discussion
      • Summary of delivered units
      • Original plan was all Getter#1 devices. Sensl now proposes a 50/50 split, Elke has proposed 80/20 plit.
      • Elton had a concern that there might be an 80/20 split might not have sufficient statistics in the no Getter devices. Elke noted that for the pixellated arrays, we will have a total of 16 3x3 units, which is plenty of statistics.
      • Decision was made to request an 80/20 split. This implies that UofR and JLab will each receive five pixellated arrays and five summed arrays. For each set of five units, 4 will be fabricated with Getter#1 processing and one will be with no Getter processing. Elton will send this request to SensL.
   2. Decision on lead thickness
      • Sampling studies (Stamatis) Media:Meeting271008.pdf. Report of work-in-progress. Three geometries studied:
        • Black: Thin lead
        • Blue: Hybrid (thin + nominal) lead
        • Pink: Nominal design lead
      • Resultion of hybrid module is about 15% better than nominal at 16 degrees
      • Comments by Will Brooks on Hall B thesis (see above).
      • What is the gain? What needs to be tested if a change is desired?
   3. Roadmap toward a decision for the Bcal readout
   • • Comments on APD's (Serguei)
   • Updates on resolution studies (Blake)
     • have simulated pi0s in both geometries, have had compiling issues with analysis code the last week
   • Visit to Alberta
     • Schedule a phone conference for followup