Difference between revisions of "GlueX Start Counter Meeting, May 31, 2012"

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# Announcements
 
# Announcements
 
# Review [[GlueX Start Counter Meeting, May 17, 2012#Minutes|minutes from previous meeting]]
 
# Review [[GlueX Start Counter Meeting, May 17, 2012#Minutes|minutes from previous meeting]]
# [https://halldweb1.jlab.org/talks/2012-2Q/sc_5_31_12.pptx Mechanical Design]
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# [https://halldweb.jlab.org/talks/2012-2Q/sc_5_31_12.pptx Mechanical Design]
 
# Read-out design
 
# Read-out design
 
# Simulation
 
# Simulation
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==Slides==
 
==Slides==
  
Talks can be deposited in the directory <code>/group/halld/www/halldweb1/html/talks/2012-2Q</code> on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2012-2Q/ .
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Talks can be deposited in the directory <code>/group/halld/www/halldweb/html/talks/2012-2Q</code> on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2012-2Q/ .
  
 
=Minutes=
 
=Minutes=
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* '''JLab''': Chuck Hutton, Mark Ito (chair), Tim Whitlatch, Beni Zihlmann
 
* '''JLab''': Chuck Hutton, Mark Ito (chair), Tim Whitlatch, Beni Zihlmann
  
prototype, measured new scint from mcneal
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==Simulation==
got time resolution about 400 ps
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200 ps upstream, downstream 400 ps
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average 350 ps
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seems that working edges really well
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scratches in perfect surface not a big deal
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no wrapping
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good job on edges from company
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confirm with simulation
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simulation workshop will help
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if you make a volume give different surfaces different properties
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geant4 simulation
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want to look at new sipm's
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Puneet Khetarpal has started work on rate studies with the new start counter geometry.
  
mechanical
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==Prototype Tests==
1 outside
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2 show start counter
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3 zoom in cables
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4 zoom in again
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gap between pcb and foam, put in a o ring to block the light, or tape
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plastic inserts between boards for light tightening
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5 zoom in more
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cutaway
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clearance between target holder and start counter support , aluminum or stainless
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stainless on stainless sticks together, screw consideration
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standoff betwewween board and holder
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inner foam will have a lip
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holder single piece, bolts to targe support tube, stainless
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6
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fernando's electronics, back connector changed
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7 electronics
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8 cutway, target and start counter
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9 side view cutaway
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10 close-up, side cutway, at upstream end
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11 foam alone
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12 close up of foam alone
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build central part, then mount counters on the outside
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Werner reported test results on the new counter from McNeal. They are getting about 200 ps resolution from the upstream end and 400 ps from the downstream. The average is about 350 ps. This is very near the design goal. SiPM's were used for the read-out with no wrapping on the scintillator. It seems that McNeal did a good job polishing the edges of the scintillator. There were some scratches on the flat sections but they appear not to effect performance.
  
nose to save material
+
Puneet would like to confirm in simulation that good edge quality results in good resolution but it is not obvious how to make a volume in Geant4 that has different surface quality on one face versus another.
outer foam now not there now to save material
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wrapping has not been decided, shrink wrap
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reflective material , one sheet, aluminized on both sides
+
  
target guys moved, made holder a bit thinner
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Werner is looking forward to trying out the new SiPM read-out system when it becomes available.
  
viable mechanical set-up
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==Mechanical Design==
  
fiu has a machine shop
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Chuck showed about a dozen [https://halldweb.jlab.org/talks/2012-2Q/sc_5_31_12.pptx pictures of the latest mechanical design]. A compromise was reached with the target design guys that resolved the space problem with the cable connector. The design has progressed a lot; we now have a model that will work in principle.
assemble scint, test them at fiu
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build central mandrill at jlab
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electronics at jlab
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werner at jlab tue and wed
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Werner pointed out that the first step is to machine the inner foam support mandrill and glue it to the metal support tube upstream of the counters. Then the scintillators can be placed on the mandrill, with reflective material between the counters, and the whole thing secured on the outside with some sort of banding or wrapping.
review contract stuff
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mcneal, feedback to them, make a couple of few more
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For now we are assuming that we do not need any foam on the outside of the counters, even though that foam was present in the CLAS design. This will reduce the amount of material seen by particles. Chuck and Mark will check with Youri Sharabian to see if there was a compelling reason to have the foam on the outside. In the nose section, we will see how much of the inner foam can be removed at the far downstream end, again to reduce the amount of material, while maintaining mechanical stability.
board with three scint prototype, with fake mandrill
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 +
We discussed the division of labor for manufacturing, assembly, and test. Although FIU does have a machine shop, we formed a consensus around having the foam mandrill and support tube machined and glued at JLab, shipping the assembly to Florida, and having FIU assemble the scintillators, plug in the electronics, and test the system. FIU would also be responsible for designing and building any jigs or tooling necessary to perform the assembly and test.
  
 +
Werner would perhaps like to build a three-counter prototype to practice assembly and gain experience with a fully-loaded SiPM read-out board (three channels per board). He will be in contact with McNeal to give them feedback on the counters delivered and to order more for the prototype. This order will also allow us to see if McNeal can reproduce the good quality of the one non-crazed counter they delivered.
  
 +
==Contract==
  
to do
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No action yet. Things are getting late. Werner will be at JLab next week and he and Mark will get the ball rolling.
 
+
ask about meeting collab wed
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talk to youri about no outer foam
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Latest revision as of 23:47, 31 March 2015

GlueX Start Counter Meeting
Thursday, May 31, 2012
10 am EDT
JLab: CEBAF Center F326/327

Agenda

  1. Announcements
  2. Review minutes from previous meeting
  3. Mechanical Design
  4. Read-out design
  5. Simulation
  6. Contract

Communication Information

Video Conferencing

Slides

Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2012-2Q on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2012-2Q/ .

Minutes

Present:

  • FIU: Werner Boeglin
  • JLab: Chuck Hutton, Mark Ito (chair), Tim Whitlatch, Beni Zihlmann

Simulation

Puneet Khetarpal has started work on rate studies with the new start counter geometry.

Prototype Tests

Werner reported test results on the new counter from McNeal. They are getting about 200 ps resolution from the upstream end and 400 ps from the downstream. The average is about 350 ps. This is very near the design goal. SiPM's were used for the read-out with no wrapping on the scintillator. It seems that McNeal did a good job polishing the edges of the scintillator. There were some scratches on the flat sections but they appear not to effect performance.

Puneet would like to confirm in simulation that good edge quality results in good resolution but it is not obvious how to make a volume in Geant4 that has different surface quality on one face versus another.

Werner is looking forward to trying out the new SiPM read-out system when it becomes available.

Mechanical Design

Chuck showed about a dozen pictures of the latest mechanical design. A compromise was reached with the target design guys that resolved the space problem with the cable connector. The design has progressed a lot; we now have a model that will work in principle.

Werner pointed out that the first step is to machine the inner foam support mandrill and glue it to the metal support tube upstream of the counters. Then the scintillators can be placed on the mandrill, with reflective material between the counters, and the whole thing secured on the outside with some sort of banding or wrapping.

For now we are assuming that we do not need any foam on the outside of the counters, even though that foam was present in the CLAS design. This will reduce the amount of material seen by particles. Chuck and Mark will check with Youri Sharabian to see if there was a compelling reason to have the foam on the outside. In the nose section, we will see how much of the inner foam can be removed at the far downstream end, again to reduce the amount of material, while maintaining mechanical stability.

We discussed the division of labor for manufacturing, assembly, and test. Although FIU does have a machine shop, we formed a consensus around having the foam mandrill and support tube machined and glued at JLab, shipping the assembly to Florida, and having FIU assemble the scintillators, plug in the electronics, and test the system. FIU would also be responsible for designing and building any jigs or tooling necessary to perform the assembly and test.

Werner would perhaps like to build a three-counter prototype to practice assembly and gain experience with a fully-loaded SiPM read-out board (three channels per board). He will be in contact with McNeal to give them feedback on the counters delivered and to order more for the prototype. This order will also allow us to see if McNeal can reproduce the good quality of the one non-crazed counter they delivered.

Contract

No action yet. Things are getting late. Werner will be at JLab next week and he and Mark will get the ball rolling.