Difference between revisions of "GlueX PID Meeting, March 19, 2010"
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[http://evo.caltech.edu EVO]: [http://evo.caltech.edu/evoGate/koala.jnlp?meeting=eueneevlv2aua2avIu direct meeting link]<br> | [http://evo.caltech.edu EVO]: [http://evo.caltech.edu/evoGate/koala.jnlp?meeting=eueneevlv2aua2avIu direct meeting link]<br> | ||
Conference Group: 800-377-8846, participant code: 77438230<br> | Conference Group: 800-377-8846, participant code: 77438230<br> | ||
| − | '''Slides''': talks can be deposited in the directory <code>/group/halld/www/ | + | '''Slides''': talks can be deposited in the directory <code>/group/halld/www/halldweb/html/talks/2010-03</code> on the JLab CUE (you have to be a member of the "halld" group). This directory is accessible from the web at https://halldweb.jlab.org/talks/2010-03/ . |
=Agenda= | =Agenda= | ||
| Line 15: | Line 15: | ||
# [[Time-of-Flight/Start-Counter/Target Meeting, March 5, 2010#Minutes | Minutes from the last meeting]] | # [[Time-of-Flight/Start-Counter/Target Meeting, March 5, 2010#Minutes | Minutes from the last meeting]] | ||
# Time-of-Flight Status: Paul | # Time-of-Flight Status: Paul | ||
| − | # [https:// | + | # [https://halldweb.jlab.org/talks/2010-03/tof_rate.pdf Rates in the TOF: Sascha S.] |
# Start Counter Status: Werner | # Start Counter Status: Werner | ||
# Target Status: Rory | # Target Status: Rory | ||
| Line 28: | Line 28: | ||
==Target== | ==Target== | ||
| − | * Chris asked about purchasing the pulse tube | + | * Chris asked about purchasing the pulse tube refrigerator and compressor he described at the [[Time-of-Flight/Start-Counter/Target Meeting, December 11, 2009#Minutes|December 11th meeting]]. He had a cost estimate of 40 k$. He will get a quot and pass it on to Eugene. |
* Tim noted that on the p3e schedule, we will purchase cryogenic supply lines for the target in January 2012. This system obviates the need for those lines. | * Tim noted that on the p3e schedule, we will purchase cryogenic supply lines for the target in January 2012. This system obviates the need for those lines. | ||
* Rory reported that Aram Teymurazyan is no longer with UMass. We wish Aram well with his new position at the University of Toronto. A new post-doc search is being organized. Hall D instrumentation will be a major part of the job description. If you know of strong candidates, let them know about the position. | * Rory reported that Aram Teymurazyan is no longer with UMass. We wish Aram well with his new position at the University of Toronto. A new post-doc search is being organized. Hall D instrumentation will be a major part of the job description. If you know of strong candidates, let them know about the position. | ||
| Line 50: | Line 50: | ||
** The new tubes performed better for timing, but are 10 stages (R10534) vs. the 12 stages of the XP2020's and so gain is a question. | ** The new tubes performed better for timing, but are 10 stages (R10534) vs. the 12 stages of the XP2020's and so gain is a question. | ||
*** hits at far end only got to 97% efficiency | *** hits at far end only got to 97% efficiency | ||
| − | *** gain 1.5x10 | + | *** gain 1.5x10<sup>6</sup> and 1.1x10<sup>6</sup> for the two tubes tested vs. 1x10<sup>7</sup> for the XP2020's |
** The Hamamatsu tubes cost about $800 with base and shield, half the cost of the XP2020 | ** The Hamamatsu tubes cost about $800 with base and shield, half the cost of the XP2020 | ||
* Sasha O. is now working on CFD vs LE (with time-walk correction) discriminator comparisons | * Sasha O. is now working on CFD vs LE (with time-walk correction) discriminator comparisons | ||
| Line 63: | Line 63: | ||
===Rates=== | ===Rates=== | ||
| − | Sascha S. showed results from a study of rates in the time-of-flight due to electromagnetic background. See | + | Sascha S. showed results from a study of rates in the time-of-flight due to electromagnetic background. See [https://halldweb.jlab.org/talks/2010-03/tof_rate.pdf his note] for details. |
| − | + | * The main message: the estimated rate of 12 MHz in the inner double-ended counters is probably too high to be acceptable. | |
| − | + | * These counters may have to be "split" longitudinally. | |
| − | + | * Beni remarked that these rates are higher than in previous studies. Those gave rates more like 3 or 4 MHz | |
| − | + | * Richard found 5 MHz was the limit for the tagger counters. | |
| − | Elton | + | * Elton asked why low energy stuff in ADC specturm was not larger in comparison the the minimum ionizing signal in the background. |
| − | + | * Sascha complained that in the reconstruction it is often difficulty to correlate hits with the Monte Carlo particles that produced them. | |
| − | reconstruction is | + | * Eugene suggested that we also look at the current going through tubes and whether they can stand it. If not we might have to go to amplifiers. |
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | might have to go to amplifiers | + | |
| − | + | ||
| − | + | ||
===MOU=== | ===MOU=== | ||
| − | + | Paul gave a report. | |
| − | Paul will send the latest | + | * Comments from others have been incorporated. |
| + | * He will talk to his chair. | ||
| + | ** Recent changes in the department make a designer available. | ||
| + | * Paul will send the latest version to everyone. | ||
Latest revision as of 23:59, 31 March 2015
Contents
Location, Time
Friday, March 19, 2010
2:00 pm EDT
JLab: CEBAF Center, Room F326/7
ESNet: 8542553
EVO: direct meeting link
Conference Group: 800-377-8846, participant code: 77438230
Slides: talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2010-03 on the JLab CUE (you have to be a member of the "halld" group). This directory is accessible from the web at https://halldweb.jlab.org/talks/2010-03/ .
Agenda
- Announcements
- Meeting name change progressing
- Minutes from the last meeting
- Time-of-Flight Status: Paul
- Rates in the TOF: Sascha S.
- Start Counter Status: Werner
- Target Status: Rory
- Action Items
Minutes
FSU: Sasha Ostrovidov
JLab: Eugene Chudakov, Paul Eugenio, Mark Ito (chair), Chris Keith, Elton Smith, Sascha Somov, Simon Taylor, Elliott Wolin, Beni Zihlmann
UMass: Rory Miskimen
Target
- Chris asked about purchasing the pulse tube refrigerator and compressor he described at the December 11th meeting. He had a cost estimate of 40 k$. He will get a quot and pass it on to Eugene.
- Tim noted that on the p3e schedule, we will purchase cryogenic supply lines for the target in January 2012. This system obviates the need for those lines.
- Rory reported that Aram Teymurazyan is no longer with UMass. We wish Aram well with his new position at the University of Toronto. A new post-doc search is being organized. Hall D instrumentation will be a major part of the job description. If you know of strong candidates, let them know about the position.
Start Counter
- Werner working on hiring for the new bridge position and the...
- ...MOU.
- Elton asked about signatures at FIU. Werner reported concerns from the Provost, though not of a alarming nature.
- He wants to talk to Tim about mechanical issues, including machining the scintillator after bending so that they fit nicely into a close-packed array.
- Seema has gone on to a new position. Werner is going to hire another post-doc.
- Werner would like to get one of the new SiPM arrays. Testing should take about a month.
- We were reminded that the nominal cross section of the counters is now 10 mm x 3 mm.
Time-of-Flight
FSU status
- Paul reminded us that their recent effort has been to choose a PMT
- The thrust was comparison of the new Hamamatsu tubes vs. the Photonis XP2020 (the latter being no longer available)
- The new tubes performed better for timing, but are 10 stages (R10534) vs. the 12 stages of the XP2020's and so gain is a question.
- hits at far end only got to 97% efficiency
- gain 1.5x106 and 1.1x106 for the two tubes tested vs. 1x107 for the XP2020's
- The Hamamatsu tubes cost about $800 with base and shield, half the cost of the XP2020
- Sasha O. is now working on CFD vs LE (with time-walk correction) discriminator comparisons
- Paul and Sasha want to add more paddles and study half-length paddles
- Need 6 more tubes for the set-up they have in mind.
- Paul will get quotes, send them to Mark, who will pass them by Eugene
- Paul is thinking of studying whether light can be coupled around hole to get two-ended read-out for the short paddles.
- Elton commented that schemes like that often have difficulty channeling enough light to make them work.
- Paul described their preparations to test flash ADC readout (VXS crate, cutting the pins to accomodate the Flash250, etc.)
- Given scarcity of the FADC's, Paul and Sasha will explore using integrating ADC's.
Rates
Sascha S. showed results from a study of rates in the time-of-flight due to electromagnetic background. See his note for details.
- The main message: the estimated rate of 12 MHz in the inner double-ended counters is probably too high to be acceptable.
- These counters may have to be "split" longitudinally.
- Beni remarked that these rates are higher than in previous studies. Those gave rates more like 3 or 4 MHz
- Richard found 5 MHz was the limit for the tagger counters.
- Elton asked why low energy stuff in ADC specturm was not larger in comparison the the minimum ionizing signal in the background.
- Sascha complained that in the reconstruction it is often difficulty to correlate hits with the Monte Carlo particles that produced them.
- Eugene suggested that we also look at the current going through tubes and whether they can stand it. If not we might have to go to amplifiers.
MOU
Paul gave a report.
- Comments from others have been incorporated.
- He will talk to his chair.
- Recent changes in the department make a designer available.
- Paul will send the latest version to everyone.
