[Halld-pid] Time-of-Flight Meeting Minutes, July 3, 2019

[Mark Ito]

Folks,

Please find the minutes here 
<https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_3,_2019#Minutes> 
and below.

   -- Mark

______________________________________________________


  GlueX TOF Meeting, July 3, 2019, Minutes

Present:

  * *FSU: * Paul Eugenio, Sasha Ostrovidov
  * *JLab: * Fernando Barbosa, Eugene Chudakov, Mark Ito (chair), Simon
    Taylor, Beni Zihlmann

There is a recording of this meeting <https://bluejeans.com/s/Ry4XE/> 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 June 19 
<https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_June_19,_2019#Minutes>. 


  * We re-agreed that we should use the scheme that Fernando is
    proposing where the cables and labels undergo minimum disruption in
    the Hall. The number will have to be adjusted via the translations
    table for the software to work.
  * Paul has asked Nick Sandoval and Chris Stanislav to transfer channel
    labeling, currently present only on the shields to corresponding
    positions on the frame. The shields will be removed during the
    upgrade and thus the label positions will be lost.
  * Fernando told us we are good on splitters in response to Mark's
    question.
  * Fernando told us we have a spare TDC in response to Beni's question.


      Late PMT delivery schedule

Mark reported that the PO for the additional 17 new PMTs for the upgrade 
as issued has a delivery date of October 25, too late for incorporation 
into new modules. He spoke with Ardavan Ghassemi of Hamamatsu. Ardavan 
will contact the factory and see if delivery can be advanced, but it is 
very unlikely that the PMTs will come early enough. From the discussion:

  * We have 25 new tubes in hand, all at FSU, plus some spares. The new
    tubes were ordered to bring the FSU supply to 48, the number of
    additional tubes needed for the upgrade. So we are 23 tubes short.
  * The new plan is to use tubes from the current array for the new
    modules. There are 40 tubes in the current array that will come down
    when modules are replaced. Paul will be traveling to JLab this month
    and will remove them from their modules as installed in the Hall. A
    manlift will be required. Radcon will have to be contacted to survey
    the tubes before removal from the Hall.

Delivery of completed modules to JLab is still on track for the end of 
July.


      Construction Update

Paul gave us an update.

  * Light guide material ordered from one of the two vendors we used
    showed reduced transmission in the UV, despite assurances that the
    modules came from the same manufacturer used by the other vendor.
    Paul showed plots of transmission data that demonstrate the effect.
    See the figures below. Additional material has been ordered and the
    sub-standard light guides are being remade.

PastedGraphic-2.png 
<https://halldweb.jlab.org/wiki/index.php/File:PastedGraphic-2.png>

  * The stock of ESR on-hand at FSU turned out to be less than expected.
    Paul contacted 3M. They do not sell ESR in the size we need (they
    sell small sheets, not rolls) but Paul was able to find an engineer
    who, after being told of the scientific value of our project,
    donated a roll for our modules.
  * All of the scintillator is now wrapped with ESR.
  * The light guides are mostly made, polished, and wrapped.
  * The gluing of light guides onto scintillator has started.
  * PMTs have been attached on some modules.
  * A test of a complete module will be done next week.
  * There is a wiki page at FSU (password required)
    <http://hadron.physics.fsu.edu/wiki/index.php/GlueX_Time-of-Flight#Time-of-Flight_Inner_Region_Upgrade>
    with information on the upgrade. Here, for example, is a diagram of
    where the various light-guides go.

InnerModLayout.png 
<https://halldweb.jlab.org/wiki/index.php/File:InnerModLayout.png>

  * The shipping box has been designed and list of materials drawn up.
    Paul will send the information to Mark to get it ordered.
  * The new iron shields (8 of them) are in-house now and will get
    primed and painted.
  * We need to follow up with Tim Whitlatch on the status of the support
    brackets.


      TOF Upgrade Geometry

Ashley had complete the new HDDS files for the upgraded TOF. She has 
checked it in on the branch "tof_upgrade" on the HDDS GitHub repository 
<https://github.com/JeffersonLab/hdds>. She showed slides with diagrams 
<https://halldweb.jlab.org/wiki/images/6/66/Tof_upgrade.pdf> containing 
all of the information needed for the new geometry, all shown in 
contrast to the analogous components of the old geometry.

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  * This page was last modified on 7 July 2019, at 18:24.

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