[Halld-pid] Time-of-Flight Meeting Minutes, April 25, 2013

[Mark M. Ito]

Find the minutes at 
https://halldweb1.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_April_25,_2013#Minutes 
and below.
   ____

GlueX TOF Meeting, April 25, 2013
Minutes

    Present:
      * FSU: Paul Eugenio, Sasha Ostrovidov
      * JLab: Eugene Chudakov, Chuck Hutton, Mark Ito (chair), Beni
        Zihlmann

Construction News

      * FSU has been spending time improving equipment in the lab.
           + The wrapping table needed additional central legs to improve
             stiffness.
           + Ian constructed three additional gluing fixtures (for gluing
             PMTs to modules)) to bring total to five, so that five modules
             can be glued at one time. Unfortunately, an endcap piece was
             missing, so this has introduced delay while waiting for
             delivery. After the fixtures are complete, and five modules
             are completed, they will be tested.
           + The storage lab has been re-arranged by Maurizio to
             accommodate more shelves, increasing capacity. Right now the
             room has a majority of the scintillators.
      * Testing of scintillators continues.
           + Sasha has to change electronics to do complete module testing,
             so for now he is trying to get ahead on scintillator testing
             while that set-up is in place.
           + Twenty-five bars have been tested. Only one bad bar was found
             (reported last time), with an attenuation length of 150 cm.
             Good ones show 250-400 cm. The specs is greater than 200 cm.
           + Beni commented on the large range in attenuation length. The
             documentation from Eljen on these bars shows similar variation
             and the tests are consistent with that documentation. Paul
             also noted that the six first-article pieces were from one or
             two batches while the production pieces are from several.
             Eugene remarked that the variation in attenuation is likely
             due to variations in surface quality after the diamond cut,
             though Paul reported that visually at least, no large
             variations have been seen. Eljen also said that the one bad
             came from near end of of a production batch where color
             changes can happen.
      * FSU is using a new method for wrapping the modules with ESR.
        Previously sutures were used to tighten the material. Ian has made
        a fixture that allows pre-folding of the ESR to its final shape.
        This saves time taping up the seam later, although the over-all
        procedure takes about the same amount of time. On the other hand,
        the pre-folded sheets can be done in bulk and saved for taping
        later.
      * Sasha described an algorithm for matching PMTs in pairs to be used
        on modules. The goal is to put together PMTs that have similar
        gain, but dissimilar noise levels. The latter requirement insures
        that no single module has a noisy tube on both ends. For details
        see [19]his webpage.
      * FSU has received the flash ADC 250 from JLab. They also got a copy
        of the driver from David Abbott. Sasha will start work on modifying
        it to use their CAEN VME controller.
      * With the added ADC channels Paul and Sasha are considering testing
        six modules at one time a la Ralf Gothe at South Carolina. That
        would saturate the high-voltage channels they have in their LeCroy
        1458 mainframe. Mark will look into getting a module to loan to
        them.

Invoicing changes and status

    JLab has not received any of the detailed invoices agreed to at the
    readiness review. Paul will check on this at FSU. Mark will ask
    Kathleen Jones if direct contact between her and FSU would be useful.

Installation plan and document

      * FSU plans to map the locations and orientation of individual
        modules in advance of shipping to JLab. Modules will be shipped in
        batches. There is shelf space

    at FSU for about half of the completed modules, although if needed,
    more storage can be found. Storage at JLab has not been worked out.
    Maurizio is looking in the size of the boxes. JLab needs that
    information to plan.
      * We will test each module after shipping to make sure it survived
        the trip.
      * Tim has started having assembly and installation meetings for the
        TOF. The last one was attended by Tom Carstens, Chuck, and Mark. We
        will try to connect FSU to the discussion in some manner soon.

    Retrieved from
"https://halldweb1.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_April_25,_2013"

References

   19. 
http://hadron.physics.fsu.edu/TOF/doc/matchmaking/PMT_matchmaking.html

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