Difference between revisions of "GlueX TOF Meeting, February 2, 2012"
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| − | Thursday, | + | Thursday, February 2, 2012<br> |
10:00 am EST<br> | 10:00 am EST<br> | ||
JLab: ARC, Room 428<br> | JLab: ARC, Room 428<br> | ||
| Line 21: | Line 21: | ||
==Slides== | ==Slides== | ||
| − | Talks can be deposited in the directory <code>/group/halld/www/ | + | Talks can be deposited in the directory <code>/group/halld/www/halldweb/html/talks/2012-1Q</code> on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2012-1Q/ . |
==Chairman's Cell Phone== | ==Chairman's Cell Phone== | ||
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There have been a couple of conference calls with the design teams on the design of the light guides for the half-width (or split) paddles. We have agreement on a final design in hand. | There have been a couple of conference calls with the design teams on the design of the light guides for the half-width (or split) paddles. We have agreement on a final design in hand. | ||
| − | Chuck showed the [https:// | + | Chuck showed the [https://halldweb.jlab.org/talks/2012-1Q/tof%20assy.pptx latest drawings], demonstrating the assembly steps we might follow on the floor of the Hall. |
We talked a little about how the thickness of the scintillator wrapping material affects the design. Paul agreed to send us numbers on the thickness. | We talked a little about how the thickness of the scintillator wrapping material affects the design. Paul agreed to send us numbers on the thickness. | ||
| Line 53: | Line 53: | ||
==Prototype Status== | ==Prototype Status== | ||
| − | Sasha showed [https:// | + | Sasha showed [https://halldweb.jlab.org/talks/2012-1Q/First%20results%20from%208-stage%20PMTs.html results] from on-going tests of the eight-stage phototubes from Hamamatsu. The gains are a several times lower than for the ten-stage, as expected, but still show good separation from pedestal. Efficiency was reduced to about 80% when using a 30 mV discriminator threshold, for triggers in the middle of the counter (no amplification). Time resolution measurements are in the works. |
==TDC Choice== | ==TDC Choice== | ||
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==Action Items== | ==Action Items== | ||
| − | Paul agreed to send us numbers on the thickness. | + | # Paul agreed to send us numbers on the thickness of the scintillator wrapping. |
| − | Mark will ask about compatibility of the CAEN VX1290 TDC with the | + | # Mark will ask about compatibility of the CAEN VX1290 TDC with the GlueX DAQ. |
Latest revision as of 05:07, 1 April 2015
Thursday, February 2, 2012
10:00 am EST
JLab: ARC, Room 428
Contents
Agenda
- Announcements
- Minutes from the last meeting
- Mechanical design: Tim, Chuck
- Prototype status: Paul, Sasha [1]
- Contract Status: Mark, Paul
Communication
Videoconference
- ESNet: 8542553
- EVO: EVO site
Slides
Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2012-1Q on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2012-1Q/ .
Chairman's Cell Phone
(757)504-0664.
Minutes
Present:
- FSU: Paul Eugenio, Sasha Ostrovidov
- JLab: Chuck Hutton, Mark Ito (chair), Tim Whitlatch, Beni Zihlmann
Minutes from the last meeting
We reviewed the minutes from the January 19th meeting. Some items received continuing discussion in this meeting. See below.
Contract
Procurement at JLab and the Office of Sponsored Research at FSU are in touch and are exchanging information about the construction contract.
Mechanical Design
There have been a couple of conference calls with the design teams on the design of the light guides for the half-width (or split) paddles. We have agreement on a final design in hand.
Chuck showed the latest drawings, demonstrating the assembly steps we might follow on the floor of the Hall.
We talked a little about how the thickness of the scintillator wrapping material affects the design. Paul agreed to send us numbers on the thickness.
Paul showed a jig, produced by his machine shop, for gluing PMT's to the light guides. The light guide is housed in an aluminum frame and there is a clamp for holding the PMT while the glue dries.
Prototype Status
Sasha showed results from on-going tests of the eight-stage phototubes from Hamamatsu. The gains are a several times lower than for the ten-stage, as expected, but still show good separation from pedestal. Efficiency was reduced to about 80% when using a 30 mV discriminator threshold, for triggers in the middle of the counter (no amplification). Time resolution measurements are in the works.
TDC Choice
Paul was wondering if there is any data-acquisition-based reason for not using the CAEN VX1290 TDC's. They see better performance with this unit than with the F1 TDC at FSU, both with a pulser and with detector pulses. They are purchasing the unit they have; up until now it has been on loan from CAEN. Paul is willing to loan it out if that helps answer any questions.
Mark promised to ask the DAQ folks if there is any fundamental reason we cannot use it.
Action Items
- Paul agreed to send us numbers on the thickness of the scintillator wrapping.
- Mark will ask about compatibility of the CAEN VX1290 TDC with the GlueX DAQ.
