[Halld-pid] Start Counter Meeting Minutes, December 12, 2013

[Mark Ito]

Dear PID list,

Find the minutes below and at

https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_December_12,_2013#Minutes 
.

   -- Mark
______________________________________________________

GlueX Start Counter Meeting, December 12, 2013
Minutes

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

Counter Construction Status

    Eric gave the report.
      * Eljen has been having yield problems due to scratches on the bent
        scintillator bars. The Q/A guy there has taken over production and
        since then, yield has improved. They have 25 bars of acceptable
        quality and should have all 50 by Christmas.
      * McNeal has been apprised of the delay. They think that their
        estimate of 4 weeks to do the work should hold.
      * FIU has decided on food grade aluminum to do the wrapping of the
        counters. The thickness is 16.5 µm.
      * Anthony (FIU student) has done several test wraps with good results
        on the barrel and nose sections. The technique on the dreaded bend
        region is the next hurdle.
      * The design of the assembly jig is largely done. The next step is to
        start ordering materials and running the design past the machine
        shop.
      * The exact mechanism for precise clocking of the inner mandrill
        still needs to be worked out.

Support Structure Construction Status

    Chuck brought in the latest inner carbon fiber tube for show and tell.
    The length of the tube has been extended from the original plan to 12
    inches. This still will not cover the nose region. We discussed whether
    three layers of carbon fiber was acceptable. Although a bit more
    material will be added than we expected, we thought that we could live
    with it.

    [Added in press: Eugene Chudakov points out that we might want to look
    at the effect of the extra material on proton detection efficiency.]

    Retrieved from
"https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_December_12,_2013"

-- 
Mark M. Ito, Jefferson Lab, (757)269-5295