Difference between revisions of "GlueX Start Counter Meeting, January 27, 2011"
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* '''JLab''': Eugene Chudakov, Mark Ito (chair), Sascha Somov, Simon Taylor, Beni Zihlmann | * '''JLab''': Eugene Chudakov, Mark Ito (chair), Sascha Somov, Simon Taylor, Beni Zihlmann | ||
| − | + | ==Wrapping Material== | |
| − | + | ||
| − | + | ||
| − | + | The ESR sheets from FSU have still not arrived. | |
| − | + | ||
| − | + | ==Materials and Construction== | |
| − | • | + | |
| − | • | + | * Lei reports a price of $190 a piece for the scintillator from Elgin. They will have with diamond milled edges. |
| + | * The pieces will be sent to Plastic Craft for cutting, bending, and polishing. | ||
| + | |||
| + | ==Neutrons and SiPM Damage Rates== | ||
| + | |||
| + | Sasha recommended that we look at Richard's [?? recent note] on the effect of SiPM dark current on the microscope counters. Some points from that note: | ||
| + | * Timing resolution is not much affected by dark rate. | ||
| + | * Looked at rates up to a gigahertz. | ||
| + | • Photonique devices with a slow recovery rate gives fluctuation in timing resolution due to non-constant exposure to beam. | ||
| + | • Hamamtsu devices have a faster recovery rate and a steadier response. | ||
measurements with new SiPM | measurements with new SiPM | ||
Revision as of 10:12, 28 January 2011
Contents
Location, Time
Thursday, January 27, 2011
3:30 pm EST
JLab: CEBAF Center, Room F326/7
Agenda
- Announcements
- Review minutes from previous meeting: all
- Start Counter News: Werner, Lei, Eric
- For pictures see http://wanda.fiu.edu/boeglinw/GlueX/SC
- MOU plans: all
Communication Information
Telephone
To connect by telephone:
- dial:
- US and Canada: (866)740-1260 (toll free)
- International: (303)248-0285 (toll call) or look up toll-free number at http://www.readytalk.com/intl
- enter access code followed by the # sign: 3421244#
Video Conferencing
- ESNet: 8542553
- EVO:
- Meeting URL: http://evo.caltech.edu/evoNext/koala.jnlp?meeting=eaeDetvlv8a9asasIa
- Phone Bridge ID: 8 5557
Slides
Talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2011-1Q on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2011-1Q/ . You have to be a member of the "halld" Unix group to do this.
Minutes
Present:
- FIU: Werner Boeglin, Lei Guo, Eric Pooser
- JLab: Eugene Chudakov, Mark Ito (chair), Sascha Somov, Simon Taylor, Beni Zihlmann
Wrapping Material
The ESR sheets from FSU have still not arrived.
Materials and Construction
- Lei reports a price of $190 a piece for the scintillator from Elgin. They will have with diamond milled edges.
- The pieces will be sent to Plastic Craft for cutting, bending, and polishing.
Neutrons and SiPM Damage Rates
Sasha recommended that we look at Richard's [?? recent note] on the effect of SiPM dark current on the microscope counters. Some points from that note:
- Timing resolution is not much affected by dark rate.
- Looked at rates up to a gigahertz.
• Photonique devices with a slow recovery rate gives fluctuation in timing resolution due to non-constant exposure to beam. • Hamamtsu devices have a faster recovery rate and a steadier response.
measurements with new SiPM • timing resolution a bit disappointing • more test with the new scintillator, with PMT ∘ light output ∘ attentuaion length • then with SiPM ∘ even with same amount of light, get factor 1.5-2 worse resolution ∘ pulse with led works well with SiPM ∘ more study needed ∘ cannot see single pe peak, pedestal is wide
50 mV signal from SiPM, amplified to 200 mV ADC uses direct signal
don't think it is the amount of light played a bit with bias voltage, nominally 71 V using what Carl ways
using cfd's
peltier element
werner will send MOU
time resolution requirement: what is it? what do we put in MOU.
E. put in purpose
W. may take some details out.
photo-detectors in a region of substantial magnetic field
sascha: use the tagger to help
total 56 K$ labor: 170 man-weeks for labor
