Difference between revisions of "December 21, 2007 Calorimetry"

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==Minutes==
 
==Minutes==
  
−
Attendees:
+
Attendees: Alex, Matt, Beni, Mihajlo (Indiana), Elton, Tim (JLab), Elke (DESY), George, Zisis (Regina)
 +
 
 +
# '''Previous minutes:''' [[December 14, 2007 Calorimetry]]
 +
#* No comments.
 +
# '''Calorimetry Document Preparation'''
 +
#* ''Resources'':
 +
#* ''Status Quo'':
 +
#* ''Timelines'':
 +
#* ''Reviewers'':
 +
# '''FCAL Hardware/Software'''
 +
#* Mihajlo has been generating gp->b_1pi0  and f_1pi0 (all neutral) final states for reconstruction studies. The learning curve on high multiplicity events is taking more time than anticipated. Hopes to have results to show soon.
 +
#* Alex mentioned that a comparison of Mihajlo's reconstruction with his parametric simulation has been conducted and agrees well. The input of photon detection for the parametric MC was parameterized from Mihajlo's output. For a_0 and a_2 production the realistic acceptance is about 30-35% and agrees between the two analysis. This reconstruction has been updated since the collaboration meeting where a 40% reconstruction efficiency was reported.
 +
#* The reconstructed masses of pi0 is about 10-11 MeV, eta is 35 MeV. The widths agree between full reconstruction and MC. For photons that hit the Fcal only, the pi0 width is about 7 MeV and photons that hit the Bcal only the width is about 11 MeV.
 +
# '''BCAL Hardware/Software'''
 +
#* George reported on the SiPM work. Two new results will be posted to the portal shortly. Conclusions from the Phase I tests are
 +
#** Quality of SiPMs fell below expectations, at least for these early units
 +
#** Factor of 2 variation in gain which is not acceptable
 +
#** The sensor tiles showed extreme sensitivity of electronics to external parameters, such as the power supply and noise. Large pedestal widths are due mainly to the electronics.
 +
#** Tested tiled arrays provide a proof-in-principle of use of detection over a large area, but characteristics are below specifications.
 +
#** Carl asked for the voltage used for the reported tests: The breakdown voltate was 27.3 V, operation was about 28.8 V or about 1.5 V above breakdown.
 +
#** SensL initially did not believe the large gain variations measured, but UofR measurements are reproducible and seem to stand up.
 +
#** SensL has asked UofR to make further tests, specifically to check the connectivity from cell-to-cell, with they will do.

Revision as of 21:37, 21 December 2007

Connection

  • The meeting will be held at 10:00 EST (9:00 CST)
  • Phone:
    • +1-800-377-8846 : US
    • +1-888-276-7715 : Canada
    • +1-302-709-8424 : International
    • then enter participant code: 39527048# (remember the "#")

Agenda

  1. Previous minutes: December 14, 2007 Calorimetry
  2. Calorimetry Document Preparation
  3. FCAL Hardware/Software
    • Light guides: ongoing, update
    • Low energy threshold: cosmics/Cherenkov: ongoing, update
    • Hadronic backgrounds: ongoing, update
  4. BCAL Hardware/Software
  5. Any other business

Minutes

Attendees: Alex, Matt, Beni, Mihajlo (Indiana), Elton, Tim (JLab), Elke (DESY), George, Zisis (Regina)

  1. Previous minutes: December 14, 2007 Calorimetry
    • No comments.
  2. Calorimetry Document Preparation
    • Resources:
    • Status Quo:
    • Timelines:
    • Reviewers:
  3. FCAL Hardware/Software
    • Mihajlo has been generating gp->b_1pi0 and f_1pi0 (all neutral) final states for reconstruction studies. The learning curve on high multiplicity events is taking more time than anticipated. Hopes to have results to show soon.
    • Alex mentioned that a comparison of Mihajlo's reconstruction with his parametric simulation has been conducted and agrees well. The input of photon detection for the parametric MC was parameterized from Mihajlo's output. For a_0 and a_2 production the realistic acceptance is about 30-35% and agrees between the two analysis. This reconstruction has been updated since the collaboration meeting where a 40% reconstruction efficiency was reported.
    • The reconstructed masses of pi0 is about 10-11 MeV, eta is 35 MeV. The widths agree between full reconstruction and MC. For photons that hit the Fcal only, the pi0 width is about 7 MeV and photons that hit the Bcal only the width is about 11 MeV.
  4. BCAL Hardware/Software
    • George reported on the SiPM work. Two new results will be posted to the portal shortly. Conclusions from the Phase I tests are
      • Quality of SiPMs fell below expectations, at least for these early units
      • Factor of 2 variation in gain which is not acceptable
      • The sensor tiles showed extreme sensitivity of electronics to external parameters, such as the power supply and noise. Large pedestal widths are due mainly to the electronics.
      • Tested tiled arrays provide a proof-in-principle of use of detection over a large area, but characteristics are below specifications.
      • Carl asked for the voltage used for the reported tests: The breakdown voltate was 27.3 V, operation was about 28.8 V or about 1.5 V above breakdown.
      • SensL initially did not believe the large gain variations measured, but UofR measurements are reproducible and seem to stand up.
      • SensL has asked UofR to make further tests, specifically to check the connectivity from cell-to-cell, with they will do.
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