[Halld-pid] Time-of-Flight Meeting Minutes, March 27, 2019

[Mark Ito]

Folks,

Please find the minutes here 
<https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_March_27,_2019#Minutes> 
and below.

   -- Mark

______________________________________


  Minutes, GlueX TOF Meeting, March 27, 2019

Present:

  * *FSU: * Paul Eugenio
  * *JLab: * Thomas Britton, Mark Ito (chair), Simon Taylor, Tim
    Whitlatch, Stephanie Worthington, Beni Zihlmann

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


      Upgrade Plan

Stephanie showed some screen shots of the current design, see below. She 
has been working on modifications to the original STEP files sent from 
Ian Winger. Known interferences have been addressed.

<https://halldweb.jlab.org/wiki/index.php/File:48cm_arrangment_Full_Assembly-_DS.png> 

Upstream Layer
	
<https://halldweb.jlab.org/wiki/index.php/File:48cm_arrangment_Full_Assembly-_DS.png> 

Downstream Layer
<https://halldweb.jlab.org/wiki/index.php/File:48cm_arrangment_Full_Assy-close_up.png> 

Close-up, one view
	
<https://halldweb.jlab.org/wiki/index.php/File:48cm_arrangment_Full_Assy-close_up_Iso.png> 

Close-up, another view

We discussed recent activities and next steps.

  * Holder brackets were adjusted. JLab ordered these pieces for the
    original TOF.
  * Ian is doing a measurement on the mini-TOF to confirm the 2-3/4" OD
    of the iron shields.
  * Paul would like to review the design from first principles with the
    2-3/4" dimension in mind (as opposed to 3"). Tim cautioned that
    there is not much space between the iron shields in the design as it
    stands.
  * FSU will machine the PMT shields and collars as they did for the
    original TOF.
  * Stephanie will send the latest design files to FSU.
  * There will be a two-foot gap between bolts used to clamp the support
    beams together in the center of the array. This has to be done to
    accommodate the new light guide configuration. This should not cause
    a problem with support of the counters.
  * We should order scintillator and light guide material ASAP. These
    are on the critical path.
  * More tubes will be needed, but not at the beginning of construction.
  * The written procedures have been pulled. Mark Stevens is looking at
    them.
  * Stephanie mentioned that an assembly bracket[?] needs redesign.


      Review of minutes from the last meeting

We went over the minutes 
<https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_March_13,_2019#Minutes>. 


Beni and Ashley will visit the Hall to confirm that there are sufficient 
spare channels on the current electronics to accommodate the upgrade.


      TOF ML

Thomas showed

 1. slides
    <https://halldweb.jlab.org/DocDB/0039/003953/001/TOF_slides.pdf>
    describing the Machine Learning system he is using on the monitoring
    histograms and results from application to the TOF. See his slides
    for the details. Some highlights:

  * The final product will use inputs from histograms for all detector
    subsystems as well as EPICS variables.
  * He is using Keras with a TensorFlow backend.
  * He is using the Inception Network, and arrangement of nodes that was
    developed specifically to do image classification[?].
  * The results for the TOF are quite good: "Good" accuracy of 99.4%
    with a 0.8% rate of false positives and "Bad" accuracy of 90.9% with
    a 0.8% rate of false positives.
  * Future work (from his slide):
      o Move to histogram values
      o Begin hooking up these nets with the super network (the final
        product mentioned above)
      o Work it into the workflow in counting house

Retrieved from 
"https://halldweb.jlab.org/wiki/index.php?title=GlueX_TOF_Meeting,_March_27,_2019&oldid=92054"

  * This page was last modified on 29 March 2019, at 17:26.

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