GlueX Start Counter Meeting, December 20, 2010

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Revision as of 21:53, 20 December 2010 by Marki (Talk | contribs) (Minutes)

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Location, Time

Monday, December 20, 2010
1:30 pm EST
JLab: CEBAF Center, Room F228

Agenda

  1. Announcements
  2. Review minutes from previous meeting: all
  3. Start Counter News: Werner
  4. Neutron flux and Start Counter SiPM's: Sascha
  5. Photodetector decision process: all
  6. MOU plans: all

Communication

Conference Group, US: 800-377-8846, Canada: 888-276-7715, International: 302-709-8424
   participant code: 77438230
ESNet: 8542553
EVO: direct meeting link, phone bridge ID: 7 7569
Slides: talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2010-12 on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2010-12/ .

Minutes

  • FIU: Werner Boeglin, Lei Guo
  • JLab: Mark Ito, Sascha Somov

Start Counter News

Wrapping material

Paul Eugenio has sent some ESR sheets sent to FIU. They have not been received yet.

Counter Fabrication

Lei has had futher contact with the company that is fabricating light guides for the CLAS12 central TOF.

  • They can do bending for no extra charge.
  • They estimate a failure rate of 3 out of 8.
  • The cost should be a few hundred dollars per counter.
  • One possibility is to buy scintillator in sheets and have the company do the cutting, bending, and polishing.
  • Practice for the company with plexiglass seems the likely next step.

Neutrons and SiPM damage rates

Sasha reviewed the damage estimates on his wiki page.

• dose comparable to bcal SiPM region • polyethylene shielding helps, studied for the tagger, factor of 7 • support structure could be made out of shielding material

• W. wants to look with new SiPM. timing dominated by light output • Richard simulated discriminator with damaged sipm, timing resolution OK with a factor of 50 increase in timing resolution, he expects 300 pe total • W. can change current with temperature. • sc rate 12 kHz, vs 1 MHz for microscope • ask Carl how hot does it have to be.

• focus on SiPM • same SiPM as BCAL • W has a 4x4 array • W has one, F10943, Hamamatsu • ask Carl for another one • language • MRI possibility

• changing set-up to do light output measurement to accomodate SiPM as main detector • new scintillators as well, 2 mm and 3 mm • 12 and 15 mm wide: 30 element for 15 mm • light output reduced by edges, wider has fewer edge area fractionally

• light guides design • • tin viewer