Time-of-Flight/Start-Counter Meeting, April 17, 2009

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Revision as of 13:44, 22 April 2009 by Marki (Talk | contribs) (Start Counter Status)

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Location, Time

Friday, April 17, 2009
2:30 pm EDT
CEBAF Center, Room F326/327
EVO: direct meeting link (we will try this first)
Conference Group: 800-377-8846, participant code: 39527048
ESNet: 8542553

Agenda

  1. Time-of-Flight Status: Paul
  2. Start Counter Status: Seema
  3. Role of Start Counter--Design Criteria: all
  4. Next meeting time

Minutes

FIU: Seema
FSU: Paul, Sasha O.
JLab: Beni,Mark I., Elton, Simon, Eugene, Chuck, Tim, Sascha S.

Time-of-Flight Status

Paul and Sasha O. presented photos and plots from work with their first prototype. There were photos of the test light guides, the test module and the testing box. Sasha showed some initial data from cosmic ray runs with the moudule. See their wiki page for details.

Start Counter Status

Seema reported on current plans. The plan for this summer is to build a prototype. 2, 3, and 5 mm scintillator has been ordered as well as a 1.4 m light guide. The plan is to use a fine-mesh pmt as the photo-detector. They will study light yield and timing. The next step will be to bend the scintillator and compare performance with the straight version and with GEANT4 simulations. They will also work on design of tooling do to the bending.

Read-out will have to include FADC channels in order to incorporate signals into the trigger pipeline.

There was a lot of discussion about various requirements for start counter performance. In general we need to have agreement on the overall goals for the detector. Among these goals are:

  • input to trigger
  • RF bucket identification
  • part of time-of-flight particle ID scheme
  • particle ID via dE/dx

These issues had been raised by Werner in a phone conversation with Mark on Thursday.

Start Counter Rates

Seema and Sascha have been studying the electromagnetic background in the start counter. There will be a GlueX note on this subject soon. They see the following:

inner radius (cm)rate per counter (kHz)
1.0400
2.0160
3.0120

recorded by Mark I.