January 4, 2008 Calorimetry

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 21, 2007 Calorimetry
2. Collaboration Meeting
   • Coordination of presentations
   • Meeting to discuss the Calorimetry Document
3. Calorimetry Document Progress: deferred to next week
4. FCAL Hardware/Software
   • Light guides: ongoing, update
   • Low energy threshold: cosmics/Cherenkov: ongoing, update
   • Hadronic backgrounds: see Mihajlo's work: Media:efficiency_theta20.pdf and Media:efficiency_theta120.pdf
5. BCAL Hardware/Software
   • SiPM Arrays: (see Wiki page)
     • discussion of SiPM Phase-I Report; see Elke's questions/comments
     • discussion of SOW (Media:SoW_PhaseII.pdf) and Phase-II proposal (Private:PhaseII.pdf); see Elke's remarks (Media:NewSOWfromSensL.pdf)
   • Outer Bcal Light Guides
     • 4x4 square test, Acceptance=40% for R=75%, lambda=251cm and Theta entrance<27.5 degrees.
     • Trapezoid 5.75, 5.4 cm sides
     • Trapezoid acceptance plots
   • Monte Carlo: ongoing, update
     • Regina
     • Gap calorimeter
6. Any other business
   • Tracker: ActionItemTracker

Minutes

Attendees: Elke, Elton, Tim, Fernando (JLab), Curtis (CMU), George, Andrei, Zisis (Regina)

1. Previous minutes: December 21, 2007 Calorimetry
   • No comments.
2. Calorimetry Document Preparation
   • Alex has produced the introduction (about 20 pages). Matt and Co. are working on the FCAL and will have a draft by the end of next week. George highlighted the BCAL sections: description, KLOE reference, fiber spectra and comparison to PMTs and SiPMs, beam test analyses, no of pe (about 20 pages). Even after pruning the document will most likely need an executive summary. Some discussion took place on the no of pe but further discussion was deferred to the collaboration meeting where the newest calculations will be shown by George. Elke suggested that the construction timelines should not be included here, as they are in the P3E documentation.
3. FCAL Hardware/Software
   • Mihajlo reported on the reconstruction effort. He showed two plots from the old and new geometry of the tracking packages. The first plot was made for photons generated uniformly from 0‑20 degrees in polar angle, full azimuth. Photon energies were between 0‑8 GeV. The plot of 0‑120 degree photons was obtained for 0 < E_gamma < 3 GeV. Single photon reconstruction required: (Egen‑Erec)/Egen < 3 sigma_E/E; (Theta_gen‑Theta_rec)/Theta_rec < 0.05. The fractional energy error sigma_E/E for 1 GeV photons in the FCAL (BCAL) was ~4% (5%). Data in red represent the new geometry while black points represent the geometry setup that was in repository for some time (my guess from June or July). The question is how the new geometry is related to the state before the

Drift Chamber review? (Richard Jones replied to this on Jan 9 saying that the plots look reasonable).

1. BCAL Hardware/Software
   • The group discussed Elke's comments (see link above) on the Phase-I Report from Regina.
   • SensL just sent their revised Phase-II proposal. We will have an internal teleconference on Jan 2 or 3 to discuss it before replying to them.
   • Elton has gotten a handle on Blake's light ray tracing, to simulate the outer layer light guides (see histos in above link). Matt mentioned that GlueX-doc-656 is a good resource for these studies. Elton will continue and let Zisis know if GuideIt will be needed for these simulations.
2. Other Issues: the difficulty in extracting up to date information from the many documents on the portal was touched upon. It seems that the Review Documents will be an excellent re-start of the documentation, rather than trying to plow through a few hundred documents and classify them as current or obsolete.
3. Next meeting: the next calorimetry group meeting is scheduled for January 4.