[Halld-pid] Start Counter Meeting Minutes, July 24, 2014

[Mark M. Ito]

Folks,

Please find the minutes below and at 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_July_24,_2014#Minutes 
.

   -- Mark
__________________________________________________

GlueX Start Counter Meeting, July 24, 2014
Minutes

    Present:
      * FIU: Werner Boeglin, Eric Pooser
      * JLab: Eugene Chudakov, Mark Ito (chair), Bruce Lenzer, Nick
        Sandoval, Tim Whitlatch, Beni Zihlmann

Review of Minutes from July 10th Meeting

    We looked at the [21]minutes. Mark needs to check on the status of an
    itemized invoice from FIU.

Electronics Trip Report

    Nick was at FIU last week, Monday through Thursday to install the start
    counter on-detector electronics. Overall the trip went well and all
    goals were accomplished.
      * ST1/ST2/ST3 boards all delivered.
      * MPOD for bias and low voltage was delivered and fired up.
      * A cosmic trigger with external counters was set-up and data taking
        started.

    A couple of minor issues:
      * The JLab laptop revoked Nick's admin privileges when it was booted
        at FIU. A work-around was found and the control software was
        installed on two personal laptops (Nick's and Eric's).
      * The ST2 cables to the ST3 were too short to run out of the chicane
        of the dark box, so the ST3 enclosure had to be placed inside the
        dark box. LEDs on the ST3 were disconnected for obvious reasons.

Detector Construction Status

    Eric gave the report.
      * Eric wrote a progress report and issued it as a [22]GlueX Note. It
        describes the polishing procedure.
      * All 50 scintillators tested before polishing and characterized. The
        worst of them were used to develop the polishing procedure.
      * Polishing procedure finalized.
           + Polish one hour with 0.3 micron alumina suspension.
           + Test timing resolution.
           + Another hour at 0.05 micron if needed.
      * Can polish 2-3 a day, total should take 2-3 weeks to finish.
           + There are two polishing stations now.
      * 49 of the counters will be polished; one will be kept as-is for
        deterioration studies.
      * Several bars have been tested multiple times over the past two
        weeks; thus far there is no sign of deterioration.
      * Camera for adjusting alignment and separation of the scintillator
        and SiPMs have been calibrated.
      * Shimming will likely have to be done.
      * Werner ask about getting 25 micron Kapton from JLab to be used for
        shimming material.
      * The gap is set by using a spacer of foil and paper to set the
        position of the scintillator.

Light Tightening

    Werner suggested that we do the final light tightening of the detector
    at JLab. All testing at FIU during construction can be done in the dark
    box at FIU. Beni pointed out that there is a large dark box in EEL 126
    that can be used for testing the scheme here. Mark mentioned that Chuck
    had proposed the same idea in a conversation last week.

    We decided to pursue this track. There are still several ideas around
    for the exact materials and procedure; they need to be finalized in
    advance of delivery of the detector to JLab.

Readiness Review Planning

    The Review will be held on Monday, August 4, at 10 am. At JLab L207 is
    reserved.

    The review committee consists of:
      * Beni
      * Bruce
      * Mark
      * Nick
      * Tim

    We looked at the [23]draft charge that Bruce circulated some time ago.
    Eric has been looking at that draft to guide his preparations. Bruce
    will be making changes to finalize the document.

    Eric will lead us through the construction procedures at the review.
    [Added in press: it would be nice to get copies of the written
    procedures to the committee in advance of the review.]

    Bruce had suggested some sort of video tour since there will not be any
    committee members on site at FIU. FIU will think about a plan for this;
    we thought that perhaps BlueJeans on a mobile device could be used.

Gain Issue

    [Added in press: we neglected to discuss the reduction in gain of the
    pre-amps after cosmic tests at FIU last week. Reduction by about a
    factor of 5 is planned.]

Action Items

     1. Look into sending Kapton sheets to FIU for use in shimming. (Tim)
     2. Finalize the Review Charge document. (Bruce)
     3. Get an advance copy of the procedures of the committee. (Eric)
     4. Raise the gain issue at a future meeting. (Mark)

References

   21. 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_July_10,_2014#Minutes
   22. 
http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2527
   23. 
https://halldweb1.jlab.org/talks/2014-3Q/FIU%20Start%20Counter%20Manufaturing%20Readiness%20Review%20Scope%20&%20Charge.doc

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