Difference between revisions of "GlueX PID Meeting, March 19, 2010"

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* 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 a previous 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
+
−
is in canada
+
−
position ran out mid feb
+
−
u of t
+
−
post doc search being organized
+
−
halld instrumentation for this position
+
−
pass the word
+
  
−
werner working on hiring and mou
+
==Start Counter==
−
wants to talk to tim
+
−
elton: signatures on mou
+
−
concerns from provost
+
−
seema contract finished at end of Jan
+
−
going to hire another post-doc, get some money from chicago
+
−
test plans for scintillator paddles?
+
−
would like to get a new sipm
+
−
an array
+
−
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?
+
−
bending not bad, machining afterward is the problem
+
−
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
+
−
+
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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
+
−
 
+
−
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===
−
  want one
+
 
−
  12-bit fadc, only one
+
* Paul reminded us that their recent effort has been to choose a PMT
−
  paul will explore using integrating adc
+
** The thrust was comparison of the new Hamamatsu tubes vs. the Photonis XP2020 (the latter being no longer available)
−
  cfd originally only for testing
+
** 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.
−
  discussion with Richard Jones
+
*** hits at far end only got to 97% efficiency
−
  caen 30 MHz rated, cfd
+
*** gain 1.5x10^6 and 1.1x10^6 for the two tubes tested vs. 1x10^7 for the XP2020's
−
  Richard at 5 MHz
+
** 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.
  
 
Beni: higher rate than older studies, more like 3 or 4 MHz
 
Beni: higher rate than older studies, more like 3 or 4 MHz
Line 100: Line 80:
 
what is effect longitudinal split
 
what is effect longitudinal split
  
−
MOU
+
===MOU===
  
 
comments incorporated, will talk with chair, changes in dept., now have designer who has transitioned to servicing entire dept, not just condensed matter
 
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.
 
Paul will send the latest update to everyone.

Revision as of 23:01, 19 March 2010

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/halldweb1/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://halldweb1.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 a previous 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 1.5x10^6 and 1.1x10^6 for the two tubes tested vs. 1x10^7 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.

Beni: higher rate than older studies, more like 3 or 4 MHz

richard found 5 MHz was the limit

Elton asks why low energy stuff in specturm is not so large

reconstruction is shitty, correlation between particle that causes hit and hit not clear

might have to have finer segmentation

what is real current going through tubes and whether they can stand it might have to go to amplifiers

what is effect longitudinal split

MOU

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.

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