[Halld-pid] Time-of-flight meeting minutes, July 18, 2013

[Mark M. Ito]

Folks,

Find the minutes below and at 
https://halldweb1.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_18,_2013 .

   -- Mark
_______________________________

GlueX TOF Meeting, July 18, 2013
Minutes

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

Review of last TOF meeting

    We reviewed the [30]minutes of the June 20th meeting.
      * There has not been any progress adding the frame-part machining at
        FSU to the construction contract. Mark with check with Kathleen
        Jones on where this stands.
      * We have been having some confusion at JLab on ordering the iron
        shields. These issues will be resolved soon.
      * Chuck will circulate an updated rendering of the rail support
        system for the TOF.
      * Paul sent Chuck the set of links to the assembly procedures being
        followed at FSU. These look like they will suffice for generating
        documentation do be archived at JLab.
      * We will schedule an installation in the next week or so.

Construction news

Module production

    Module production is going forward at the rate of about 8 per week for
    wrapped modules with light guides and PMTs attached. Paul hopes to
    finish by the end of August or early September.

    The finished modules are tested for light leaks before wrapping with
    protective felt.

    The full cosmic testing procedure is still being developed, but when
    that is in place six modules a day can be tested.

Re-polishing light guides

    It was thought that light guide polishing was finished, but about 40 of
    them were found with sub-standard surface quality. These were from
    early in production. They will be re-done.

New shelving

    FSU is building new shelving in several of the work areas to store
    modules: the high bay, testing lab, and wrapping lab. That way if a
    room is not ready to accept modules from a previous step, those modules
    can be stored in the room where the previous step was performed, rather
    than moving them to the final storage room in the basement.

Personnel

      * Engineering student has taken job in Atlanta and will be moving.
      * A new student started today, one or two more will be hired.
      * Two students that are continuing in their jobs have to move from
        the university for three weeks due to the end of the summer term.

PMT clippers

    Ian Winger has designed and built a [31]tool for easily and cleanly
    breaking the epoxy joint between the light guide and the PMT in case
    this needs to be done in the Hall in the future. It has been tested
    with old PMTs and works well. It is not very long, but in any case
    Chuck will check the drawings and see if there is sufficient space
    around the PMTs to apply the tool should it become necessary.

    FSU will develop a documented procedure for replacing a PMT. They will
    use the mini-TOF to test the process.

FADC spectrum

    Sasha showed a [32]spectrum of integrated pulses from the FADC-250.
    Data was obtained from a 5-counter set-up and the trigger was a 10-fold
    coincidence (5 counters, 2 ends each). Since Fernando replaced the
    fuses, the one Flash that Sasha has been using has been on for about
    two weeks now. Clipped pulses are visible and there is mysterious bump
    at low pulse-height. Sasha is trying to decide where to set the HV for
    the tests.

    Mark reported that he and Beni had been looking at reflections from the
    50/50 splitters. Reflections are seen, but are not large.

SeeVogh

    We decided to discontinue use of SeeVogh for the TOF meetings now that
    we are using ReadyTalk for desktop sharing.

New Action Items

     1. Check with Procurement on contract modification.
     2. Get the steel shield raw material ordered and shipped.
     3. Circulate updated rail support design.
     4. Find a time for an installation meeting.
     5. Finish study of reflections from the splitter.

Retrieved from 
https://halldweb1.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_18,_2013

References

   30. 
https://halldweb1.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_June_20,_2013#Minutes
   31. http://hadron.physics.fsu.edu/wiki/index.php/PMT-Clipper
   32. http://hadron.physics.fsu.edu/~ostrov/tof/fADC.png

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