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)
   • 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) and has sent the material to Alex for integration. 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).
4. BCAL Hardware/Software
   • The group discussed Elke's comments (see link above in the agenda) on the Phase-I Report from Regina. Cosmetic changes will be implemented soon. Zisis will help George on this. Clean power and regulators were discussed for these tests and Fernando will provide more info to Regina. Action items from Elke's comments:
     • Item 4: perform more detailed measurements of noise (Carl)
     • Item 10: get scope traces of noise for G6 with G3 board (Andrei)
     • Item 13: measure gain variation across individual 3x3mm^2 samples (Carl)
   • The SensL revised Phase-II proposal and our SoW were discussed. The cost is significantly higher, but more is being delivered. Questions arose about the SensL work on electronics, the cost of the PDE spec change from 12 to 21%, descoping one of the strands, ask from clarifications on the monolithic strand. It was decided to meet with Carl Jackson from SensL on Monday, January 7 and 2pm EST at JLab. Regina will tie in via ESNET and Padraig Hughes will call in from Cork.
   • Elton deferred the bulk of the presentation on his light guide studies until the collaboration meeting. Quickly it was mentioned that he used 75% reflectivity and that the light guides give 20-45% transmission. There were questions on the attenuation length for acrylic and we will look this up.
5. 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.
6. Next meeting: the next calorimetry group meeting will be scheduled after the collaboration meeting.