[Halld-pid] Time-of-Flight Meeting Minutes, July 31, 2019

[Mark Ito]

Folks,

Please find the minutes here 
<https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_31,_2019#Minutes> 
and below.

   -- Mark

_____________________________________________


    GlueX TOF Meeting, July 31, 2019, Minutes

Present:

  * *FSU: * Edmundo Barriga, Ashley Ernst, Paul Eugenio, Sasha Ostrovidov
  * *JLab: * Mark Ito (chair), Tim Whitlatch

There is a recording of this meeting <https://bluejeans.com/s/jjmiz> on 
the BlueJeans site. Use your JLab credentials to access it.


      Review of minutes from the last meeting

We went over the minutes from the meeting on July 17 
<https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_17,_2019#Minutes>. 
Mark got the shipping authorization and the modified loan agreement in 
place so that Paul could take the PMTs down to FSU.


      Upgrade Status

Paul was at JLab last week and worked with engineering and technical 
staff in the Hall. The week's activities went well:

  * The TOF was un-mounted and dis-assembled. See the photo above.
  * Modules were inspected for damage. All light guides and phototubes
    were intact. There were only minor tears in the Tedlar wrapping in a
    few locations.
  * Nearly all the vertically-oriented modules showed a significant
    shift (up to an inch) in the downward direction relative to the iron
    shields and thus relative to the frame. The bottom tubes were
    sticking out, the top tubes were recessed in their shields.
      o Nylon bolts will be threaded through new tapped holes in the
        bottom row of shields to provide a physical stop against motion
        of the tubes in their shields.
  * The rubber strips that are compressed the between the steel frame
    and the scintillator needs to be replaced.
  * Also, the soft foam padding that supports the light guides in their
    channel will be replaced. Paul will send Tim his records of the
    material we used last time.
  * All modules will need to be tested. Edmundo and Jason Barlow
    (students from FSU) will arrive next week to perform the tests. JLab
    folks need to help get them set up with a scope and HV supply as
    well as room to work in the Hall.
  * There are some new holes that need to be drilled in the frame for
    the new positions of the inner modules. The frame will be completely
    disassembled to drill those holes. Records of relative orientation
    and location of any shimming will be made first.
  * The new modules will be shipped directly to the Hall, not staged in
    ESB as they were last time.
  * Paul will check progress of the machine shop on the remaining collars.
  * All of the short modules have been tested at FSU.
  * There were a few modules where the light guide ends were buffed
    after polishing, potential compromising the strength of the glue
    joint. Paul has been mechanically stressing the joints to make sure
    no weak ones make it through.
  * Tim had asked Stephanie Worthington to produce drawings of the
    acrylic beam hole support box from the 3-D model and send them to Paul.
  * Mark asked Paul to send him the serial numbers of the tubes that
    were mounted on scintillators Y-22, Y-23, Y-24, and Y-25 (short
    modules, oriented horizontally) to confirm their locatio in the
    (legacy) channel map he is putting together.


      Software Issues

Ashley reported that the reconstruction software has been changed by 
Sean to reflect the upgrade based on the geometry prepared by Ashley. 
They are in the process of testing and hope to produce monitoring 
histograms from simulated bggen data.

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  * This page was last modified on 31 July 2019, at 16:46.

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