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/halldweb1/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://halldweb1.jlab.org/talks/2010-03/ .
+
'''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=
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# [[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://halldweb1.jlab.org/talks/2010-03/tof_rate.pdf  Rates in the TOF: Sascha S.]
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# [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
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==Target==
 
==Target==
  
−
* Chris asked about purchasing the pulse tube??? refrigerator and compressor he ???described at a previous meeting. He had a cost estimate of 40 k$. He will get a quot and pass it on to Eugene.
+
* Chris asked about purchasing the pulse tube refrigerator and compressor he described at the [[Time-of-Flight/Start-Counter/Target Meeting, December 11, 2009#Minutes|December 11th meeting]]. He had a cost estimate of 40 k$. 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.
+
* 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.
−
sasha asks about aram
+
−
could not get back to us from
+
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is in canada
+
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position ran out mid feb
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u of t
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post doc search being organized
+
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halld instrumentation for this position
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pass the word
+
  
−
werner working on hiring and mou
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==Start Counter==
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wants to talk to tim
+
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elton: signatures on mou
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concerns from provost
+
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seema contract finished at end of Jan
+
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going to hire another post-doc, get some money from chicago
+
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test plans for scintillator paddles?
+
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would like to get a new sipm
+
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an array
+
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if power supplies are the same, testing should take a month
+
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10 mm x 3 mm counters
+
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bending plastic?
+
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bending not bad, machining afterward is the problem
+
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bend then machine the sides to make them fit into an array
+
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sascha asked about thickness
+
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40 to 60 cm attenuation length
+
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light tranport the problem
+
−
+
−
time-of-flight: Paul
+
  
−
big question, choice of pmt's
+
* Werner working on hiring for the new bridge position and the...
−
  thrust was comparison of new hamatsu tubes vs xp2020
+
* ...MOU.
−
  new tubes performed better, but were 10 stages h10534
+
** Elton asked about signatures at FIU. Werner reported concerns from the Provost, though not of a alarming nature.
−
  hit at far end only got to 97%
+
* 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.
−
  gain 1.5, 1.1 from not-optimal tube
+
* Seema has gone on to a new position. Werner is going to hire another post-doc.
−
  about $800 w/ base and shield, half cost of xp2020
+
* Werner would like to get one of the new SiPM arrays. Testing should take about a month.
−
  xp2020's gain 1x10^7
+
* We were reminded that the nominal cross section of the counters is now 10 mm x 3 mm.
−
  sasha working on cfd vs le comparisons
+
−
 
+
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have two tubes now
+
−
  want to add more paddles
+
−
  want to study half length paddles
+
−
    can light be coupled around hole to get two-ended read-out
+
  
−
paul will get quotes, send them to mark
+
==Time-of-Flight==
  
−
adc's, vxs crate, cut the pins, slots modified
+
===FSU status===
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  want one
+
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  12-bit fadc, only one
+
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  paul will explore using integrating adc
+
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  cfd originally only for testing
+
−
  discussion with Richard Jones
+
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  caen 30 MHz rated, cfd
+
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  Richard at 5 MHz
+
  
−
Beni: higher rate than older studies, more like 3 or 4 MHz
+
* 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 1.5x10<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
 +
* 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.
  
−
richard found 5 MHz was the limit
+
===Rates===
  
−
Elton asks why low energy stuff in specturm is not so large
+
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.
  
−
reconstruction is shitty, correlation between particle that causes hit and hit not clear
+
* 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.
  
−
might have to have finer segmentation
+
===MOU===
  
−
what is real current going through tubes and whether they can stand it
+
Paul gave a report.
−
might have to go to amplifiers
+
  
−
what is effect longitudinal split
+
* Comments from others have been incorporated.
−
 
+
* He will talk to his chair.
−
MOU
+
** Recent changes in the department make a designer available.
−
 
+
* Paul will send the latest version to everyone.
−
comments incorporated, will talk with chair, changes in dept., now have designer who has transitioned to servicing entire dept, not just condensed matter
+
−
 
+
−
Paul will send the latest update to everyone.
+

Latest revision as of 23:59, 31 March 2015

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

  1. Announcements
    • Meeting name change progressing
  2. Minutes from the last meeting
  3. Time-of-Flight Status: Paul
  4. Rates in the TOF: Sascha S.
  5. Start Counter Status: Werner
  6. Target Status: Rory
  7. 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.
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