Sep 29, 2008 Calorimetry

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Revision as of 13:57, 29 September 2008 by Elton (Talk | contribs) (Minutes)

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NEW TIME Time: 11:15 ET.

  • Phone:
    • +1-800-377-8846 : US
    • +1-888-276-7715 : Canada
    • +1-302-709-8424 : International
    • then enter participant code: 39527048# (remember the "#")

Items for followup from Sep 2 calibration meeting

  1. Each subsystem must complete blanks in the Specification Table.

Items for followup from Sep 15 meeting

  1. George: report on trip to Edmonton
  2. Decision on Bcal sampling fraction needed by Sep. - Initial work by Stamatis was reported
  3. Resolution studies (Blake)
    • 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
  4. Study impact of inactive material at the end of Bcal on acceptance.
  5. Add F100 rad hard glass to simulation. - New graduate student has been assigned this project.

Documents to Review

  1. From Will Brooks: http://www.jlab.org/Hall-D/software/wiki/images/0/0c/Geometry_effect_timing.pdf
  2. Update on VLPCs (Werner) [1]

Tentative Agenda

  1. Announcements
  2. Results on study of increased sampling in BCAL
  3. Bcal
  4. Fcal

Minutes

Attending: JLab: Elton, Beni, Elke; Athens: Christina; UofR: Zisis, George, Andrei, Stamatis; Santa Maria: Will, Sergei; FIU: Werner; IU: Matt, Mihajlo, Claire, Ryan

  1. Calibration (Christine)
    • Constructing box to shield laser from RF noise to check stability of laser
    • Looking to purchase more LEDs. The LED they are using does not presently give sufficent light.
    • All groups are encouraged to fill in the Table of Specifications.
  2. Announcements (Elton and Elke)
    • The latest news from DOE is that the 12 GeV project will not be considered a 'new start' under a continous resolution. This could allow placing orders for construction early in the fiscal year. However, budgets are still constrained by the 2008 ped funding profile.
  3. Increased sampling fraction (Zisis)
    • Simulations are continuing. For thin lead sheets the energy resolution blows up.
    • Hybrid solution results in non-uniformities and is discouraged as a general rule. Also complicates calibration. At the moment the simulation program does not lend itself directly to this option (Matt).
  4. Bcal timing and geometrical effects (Will)
    • Study implications of timing resolution in a toy model, Look at position dependent changes in mean time as a function of position. Assumes low TDC thresholds.
    • For charged particles and showers, RMS ~ 240/sqrt(12) = 80 ps. This dispersion migh in principle lend itself to software corrections for accurate modeling.
    • For neutrons, RMS ~ 70 ps, intrinsic due to the unknown neutron interaction position. Distinguishing photons from neutrons is important especially for nuclear targets.