Minutes 060707

From GlueXWiki
Jump to: navigation, search

Attendees: Matt, Eric (Indiana), David L., Elliott, Simon (JLab), Dan Sober (CU), Blake, Rafael, Zisis (Regina)

  1. Business Arising
    • Weekly meetings: We decided to have our meetings weekly from now on, and on Tuesdays, so that Elliott can better communicate decisions/actions to the Hall-B Engineers during their Thursday meetings. The time will be 12:30 EDT.
    • Schedules/Manpower: A new page (Hall-B Schedule) has been created on the Wiki where schedules, travel dates and personnel info can be posted.
    • Collimator: Based on a lengthy discussion offline and calculations by Matt (Hall-B Collimators and Flux) it was decided that the 2.6-mm collimator is adequate for our beam test, based on the following. a) Simulations show that there is no discernable difference in the energy leaking out the side of the module between a 1-mm and 2.6-mm collimator. b) Analytical calculations show that the contribution of the 2.6-mm to the z-position resolution are not a show-stopper for the extraction of sigma_z. Monte Carlo simulations are planned to verify this, however, this decision has been communicated to the H-B engineers.
  2. Detector Setup/Mechanics
    • Regina: Zisis ordered 50 Si cookies (optical interface pads) and two 10.5"x13" Si sheets , both 3-mm thick that will be shipped soon (7-10 days) to Indiana. One of these sheets suffices to cover both ends of the module. It was decided that standard mu-metal thickness would suffice for our tests, since no large/stray fields are expected in the alcove. Zisis will order mu-metal sheets sufficent to cover the light-guide boxes in a few days. 25 Burle PMTs will be shipped to JLab for the tests (18 plus 7 spares). Regina will try to do a rough gain-match using cosmics before shipping. Regina will investigate obtaining black cloth (or black cocking) for light-proofing the BCAL ends and light-guide box. The sides of the module will be painted black as well, to cover exposed fibers. Elton will check out hte experience of H-B in this regard. Regina will also provide above/below paddle counters to provide cosmics trigger.
    • Indiana: Work is progressing well although there is a machine shop crunch at IU. CMU and FSU are being contacted to see if they can machine some of the required parts for the cart and light-guide box. Nevertheless, we are still in good shape to meet the shipment deadlines to JLab. Chris is investigating a new polishing method that seems to yield spectacular results. Indiana will provide bases for the Regina PMTs and these have a built-in splitter for the anode signal.
  3. Hall-B Tasks:
    • Alcove, beamline: Elliott summarized yesterday's teleconference with the H-B engineers. Things are progressing on schedule with a completion date of August 15th and an expected occupation date of August 25th by us. We need to communicate our needs re craning, alignment, surveying to the engineers as soon as possible. Eric will review the issue of extending the plate into the alcove for a smoooth rolling of the cart and provide feedback to Elliott/H-B engineers.
    • Beam profile monitor and Veto: The Primex BPM ([1]) was found and will be used, by plugging it into the H-B patch panel and we will use their readout system. New cables (signal and low voltage) need to be made. Elliott will ensure that the LeCroy HV supply has adequate modules to supply power to this device as well. Elton has located a veto to sit right behind the BPM (see Veto counter). The combined depth (along z) of these devices should be less than one foot. Eric will investigate possible interference with the cart.
    • Cables/Electronics/Trigger: Elliott will try to get at least one fast scope (analogue if possible) for use in the alcove. If others can bring a protable scope that would be great. Also, Digital Volt Meter, lemo connectors, BNC-to-lemo and other tools may be obtained at H-B but spares wouldn't hurt. Regina can bring some of this.
    • Tagger: Nothing to report.
    • DAQ/Online software
      • Coda/Coda-lite: The initial focus is to readout the CLAS stuff first and then our own. New network switches will be available by the middle of next week.
      • Online macros/checks: David and Zisis will carry this discussion offline.
      • e-log: The MySQL database is set up. Greg Riccardi will have the first working version in 1-2 weeks.
  4. Monte Carlo:
    • Simulations by Blake on the position and angular configurations for the beam tests are available online ([2], [3]).
    • New simulations planned: materials in beamline, misalignment (vertically), cosmics configuration, pencil beam vs finite collimator size.
  5. Any other business
    • Shipping list: Regina and Indiana will work on this online and posted to the Hall-B Schedule page.
    • Run Plan/Beam and Silo Request: Elton, David and Zisis will carry this discussion offline.

Action Items


  1. Alcove/beamline: Elliott, Zisis and Eric S. will work out details and communicate to H-B engineers.
  2. BPM, Veto: David and Elliott will work on making this a functioning system.
  3. Cosmics counters: Regina will provide.
  4. Mu metal foil: Zisis will order soon.
  5. Electronics: Elliott and Zisis will run through the checklist.
  6. Tagger and Trigger: Paul Smith, Elliott, Franz Klein and Zisis will refine the trigger logic and tagger demands offline.
  7. Data storage/Silo Request: David and Zisis will deal with this offline.
  8. E-log: Greg Riccardi continues work on the GlueX e-log.
  9. Collimator: Rafael will simulate collimator size effect on sigma_z plus other effects (see above).
  10. Online Macros/MC Data steam/MC Validation & Binning: David and Zisis will work on these offline. Zisis will provide requirements for ROOT trees.
  11. Beam Request: Elton, David and Zisis will carry this discussion offline.