[Halld-pid] Start Counter Meeting Minutes, March 7, 2013

[Mark M. Ito]

Find the minutes below and at 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_March_7,_2013
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GlueX Start Counter Meeting, March 7, 2013
Minutes

    Present:
      * FIU: Eric Pooser
      * JLab: Chuck Hutton, Mark Ito (chair), Beni Zihlmann

Announcements

    Puneet Khetarpal has gone on to another job. We thank him for his
    contribution to the start counter effort at FIU, and congratulate him
    on his new position.

SiPM read-out status

    Eric got feedback from Fernando Barbosa; he should include the
    attenuation in the cables in his estimate for the required gain for the
    SiPM readout.

    More importantly, he suspects that his previous measurements used a 5X
    amplifier and its effect was not taken into account in his
    calculations. He will remeasure this afternoon.

Counter Construction

    Chuck Hurlbut at Eljen told Eric last week that they are about two days
    away from finishing the bending fixture and scintillator would be ready
    to ship to McNeal in a week or two.

    Eric also reported that he has a new contact at McNeal, Renee, who is
    handling the FIU account.

    Eric is starting on a design for the test stand for the detector. It
    will use complete three-channel SiPM read-out boards.

    A final decision on wrapping has not been made. Likely it will be
    aluminized mylar around the scintillator. We have to decide on whether
    individual counters will be light-tightened with Tedlar or if we rely
    on wrapping with an exterior layer only. If significant thickness is
    added between counters it should be reflected in the dimensions of the
    inner foam support since counter dimensions are fixed at this point.

    According to the milestones in the proposal, it looks like the inner
    foam support needs to be ready sometime in June.

VME discriminator for FIU

    We confirmed that FIU could use a discriminator or two for the the full
    detector test. Mark will work on getting them the unit(s).

Light pulsing system or not?

    Talking to folks at JLab, Mark reports that folks thing that light
    pulsing would be useful, but also that it was a lot of effort and we
    should think carefully about whether it is worth that effort at this
    stage of the project. We will have to discuss this further. Mark will
    check and see if CLAS had any such system for their start counter.

Installation Document

    At last week's installation meeting, Curtis showed an installation
    document for the CDC, essentially a plan with a timeline. We should
    develop a similar document for the start counter: what needs to be done
    and when, noting any dependencies on other installation or services in
    the Hall.

Contract

    Werner told Mark that the technical proposal would go the university
    this week for inclusion in the proposal for the construction contract.

Action Items

     1. Decide on wrapping scheme.
     2. Get discriminator(s) for FIU.
     3. Ask about light pulsing for the CLAS start counter.
     4. Start thinking about an installation document.

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-- 
Mark M. Ito, Jefferson Lab, marki at jlab.org, (757)269-5295