GlueX TOF Meeting, November 10, 2011
Thursday, November 10, 2011
10:00 am EDT
JLab: CEBAF Center, Room F326
Contents
Agenda
- Announcements
- Minutes from the last meeting
- Mechanical design: Tim, Chuck
- Prototype status: Paul, Sasha
- Contract Status: Mark
Communication
Videoconference
- ESNet: 8542553
- EVO: EVO site
- direct meeting link
- Phone Bridge ID: 10 4388
Slides
Talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2011-4Q
on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2011-4Q/ .
Minutes
Present: FSU: Sascha Ostrovidov JLab: Eugene Chudakov, Chuck Hutton, Mark Ito (chair), Beni Zihlmann
Mechanical Design
Chuck presented the current status of [??? drawings] on how to support the counters, in particular how to secure the light guides, phototubes, and shielding sleeves. Much more realism has been added, among other features, a set of collars to attach the steel shielding to the support structure.
Contract Status
Mark reported that we have drafts of all documents needed to start the procurement process: statement of work, sole source justification, specifications for both PMT's and scintillator, and drawings. There are still some edits to do, however, and nothing has been signed yet.
Prototype Status
Sasha reported work in three areas.
Non-mixed set of splitters
Measurements were done where the splitters were the same on all six channels of the prototype. He tried two configurations: a set of 50/50 splitters and a set of 80/20 splitters. He measured the following time resoltions for mean time in a single layer:
split | resolution (ps) |
---|---|
50/50 | 110 |
80/20 | 107 |
measurements of six equal splitters, not much change 50/50 110 ps mean time one plane 80/20 107 ps
reflections
pulser, no reflections, 10 ns wide, no reflections with pmt see reflections shape of signal from pmt different only reflection
8 stage pmt
tried to test with a source gain looks 5x10^5 4 or 5 time smaller than 10-stage put them into set-up. do not get separation of pedestal nim amplifier to see if can better separation pedestal more than 10 counts at 300 counts, signal at 400 counts gate 150 ns
10 counts/pc * 150 ns * v = 10 counts
americium source