[Halld-pid] Minutes, Start Counter Meeting, June 2, 2011

[Mark M. Ito]

Find the minutes at 
http://www.jlab.org/Hall-D/software/wiki/index.php/GlueX_Start_Counter_Meeting%2C_June_2%2C_2011#Minutes 
and below.

   ==

GlueX Start Counter Meeting, June 2, 2011

Minutes

    Present:
      * FIU: Werner Boeglin, Lei Guo
      * JLab: Mark Ito (chair), Sascha Somov, Beni Zihlmann


Fiber Order

    Lei contacted Kuraray and ordered 1 × 1 mm fibers. They have arrived.
    They will be clamped into a shape that can be attached to a
    scintillator.

Scintillator Order

    The scintillator will arrive from Plastic Craft by June 13.

Resolution Studies

    Werner is doing measurements with the SiPM array he has to try to
    understand the source of the timing variance. Using a leading-edge
    discriminator he is trying to predict the resolution one should expect
    from the width of the pedestal (noise), and the measured rise time of
    signals. He corrects for time walk in software. So far he sees
    resolution consistent with noise driving the observed resolution.

SiPM's for FIU

    The SiPM's that [36]Sascha ordered some time ago have arrived, again,
    some time ago. Fernando has made pre-amps for single 3 × 3 mm cells of
    two varieties, one with a gain of 35, the other with 70. Measurements
    in Vitaly Baturin's set-up look good. Sascha is trying to create our
    own set-up so we can do the tests ourselves.

    Werner is anxious to test any of the new SiPM configurations we can get
    to him. So far he has only been working with an array with an older
    version of the pre-amp. He will be here next week and will talk to
    Fernando about getting something to take back to Miami.

Segmentation

    Werner is still considering segmentation of 30 counters rather than the
    nominal 40. If the thickness is kept constant then this might help
    light output since the higher aspect ratio of the cross-sectional area
    has more perimeter on the faces relative to the edges. Previous studies
    showed that a large part of the light loss was coming from the edges of
    the scintillator.

MOU Status

      * Sent latest version to Allison on May 5.
      * Got comments from Glenn Young on May 17.
      * Sent Glenn's comments to Werner today.
      * Will incorporate Glenn's comments and re-submit to Allison.

    We agreed that we should not wait for the MOU to be signed before
    starting work on the construction contract. Werner mentioned that he
    does not have easy access to a designer at FIU. As such, the drawings
    will be done here as they have been done for other detectors.

    Retrieved from
    
"http://www.jlab.org/Hall-D/software/wiki/index.php/GlueX_Start_Counter_Meeting%2C_June_2%2C_2011"

References

   36. https://mailman.jlab.org/pipermail/halld-pid/2011-April/000159.html