Difference between revisions of "GlueX Start Counter Meeting, June 28, 2012"
(→Read-Out Design) |
(→Mechanical Design) |
||
| Line 45: | Line 45: | ||
==Mechanical Design== | ==Mechanical Design== | ||
| − | |||
| − | |||
| − | |||
| − | + | Mark talked to Youri Sharabian about the Hall B start counter: | |
| − | + | ||
| − | + | * the outer foam was for protection only | |
| − | + | * the inner foam was made of single piece of [http://www.generalplastics.com/products/rigid-foams/ Last-A-Foam] from [http://www.generalplastics.com/ General Plastics]. | |
| − | + | ||
| − | + | See [https://mailman.jlab.org/pipermail/halld-pid/2012-June/000351.html Mark's email] for details. | |
| + | |||
| + | Werner has been thinking about the jig for assembling the complete detector. He is thinking of using pneumatically driven pins to hold the counters in place before an outer wrapping is done. That way the pressure can be controlled more easily than with set screws. Tim will look into candidate parts for doing this. | ||
==Contract== | ==Contract== | ||
Revision as of 10:32, 29 June 2012
GlueX Start Counter Meeting
Thursday, June 28, 2012
10 am EDT
JLab: CEBAF Center F326/327
Contents
Agenda
- Announcements
- Review minutes from previous meeting
- Mechanical Design
- Read-out Design
- Simulation: Start Counter Background Studies
- Contract
Communication Information
Video Conferencing
- ESNet: 8542553
- EVO:
- Direct meeting link
- Phone Bridge ID: 13 2615
Slides
Talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2012-2Q on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2012-2Q/ .
Minutes
Present:
- FIU: Werner Boeglin
- JLab: Eugene Chudakov, Chuck Hutton, Mark Ito (chair), Beni Zihlmann
Prototype Testing
- Eugene asked how Werner's recent timing resolution measurements were done, with cosmics or a source. Werner used a Sr90 source with a trigger counter on the opposite side of the start counter paddle from the source. The end-point of the beta spectrum is 2.2 MeV, so the 3 mm thick start counter filters out the low energy electrons. Werner has done tests before on different counters using both cosmic rays and the Sr90 source and those have been consistent with each other.
Werner is still planning to buy two or three counters from McNeal.
Werner expressed some concern in using the relatively think VM2000 material to isolate the counters from each other. He was concerned that the thickness might add mechanical pressure and degrade the reflectivity of the edge surfaces. He will try various materials in the three-counter prototype to see if other materials do better, for example double-sided aluminized mylar.
Read-Out Design
The circuit boards for the SiPM read-out have come back and Nick Sandoval has assembled some using the 50 micron SiPM's we have on hand. The plan is to use 100 microns in the final detector; some of those are due in this week. Fernando Barbosa reported that we are still waiting for the mini-coax cable that routes connections to the break-out board.
Mechanical Design
Mark talked to Youri Sharabian about the Hall B start counter:
- the outer foam was for protection only
- the inner foam was made of single piece of Last-A-Foam from General Plastics.
See Mark's email for details.
Werner has been thinking about the jig for assembling the complete detector. He is thinking of using pneumatically driven pins to hold the counters in place before an outer wrapping is done. That way the pressure can be controlled more easily than with set screws. Tim will look into candidate parts for doing this.
Contract
start on the con today, send example to werner, mark
Simulation
puneet background studies, issues to resolve 10^7 running, 5 and 50 kHz for em background
puneet will report in two weeks
