Difference between revisions of "Minutes-6-16-2011"

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# Other
 
# Other
  
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= Minutes =
 
= Minutes =
  
Participants: Eugene, Bill, Dave, Chris, Caleb, Beni, Simon, and Lubomir.
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Participants: Eugene, Bill, Glenn, Dave, Chris, Beni, Simon, and Lubomir.
 
   
 
   
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== Other ==
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At the beginning of the meeting Bill and Dave, representing also other non-physicists, expressed interest in learning more about drift chambers, GlueX detectors and physics and beyond. Eugene, Simon, Beni were happy to answer their questions. We all agreed also to organize a special presentation for them.
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== Production ==
 
== Production ==
  
- End of last week we assembled the first production chamber, run gas over the weekend, on Monday applied HV and was tripping (1uA threshold) at very low voltages: ~20-30V for sense wires and somewhat higher (~30V, one sector was at -500V for short time) for field wires. Then we found ~1-10MOhm between HV and ground and practically all the pads on the PCBs, even between opposite PCBs on the wire frame that have no electrical connection. The conclusion was: the wire frame got wet (most likely the Rohacell) when it was cleaned in the ultrasonic bath. We tried to dry it with a lamp and then with a heat gun; didn't work. Then today we put it a big vacuum chamber at the Test Lab to take the moisture out. The person servicing the vacuum chamber mentioned that it went down to 10^-4 torrs for ~2hours, much slower than usual (~20min) which indicates there was a lot of moisture there. We will keep it there by tomorrow morning when we expect 10^-7 torrs. Bill: such under pressure will not damage the Rohacell.
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- The good news is that the gas leakage of the first package was very low (undetectable) except at one place: one of the tube on the spacer ring. Mark Stevens was yesterday at Blue Crab explaining the procedure for gluing the gas tubing on a new spacer ring; the first one will be fixed too.  
 
- The good news is that the gas leakage of the first package was very low (undetectable) except at one place: one of the tube on the spacer ring. Mark Stevens was yesterday at Blue Crab explaining the procedure for gluing the gas tubing on a new spacer ring; the first one will be fixed too.  

Revision as of 17:44, 16 June 2011

June 16, 2011 FDC meeting

Agenda

  1. Production (Dave)
    • First chamber tests (Lubomir)
    • Second set wire frame and cathodes
    • Other
  2. Engineering (Bill)
    • New encoder
    • Gusset ring
    • Other
  3. Electronics update (Fernando, Chris)
  4. Chamber testing at EEL126 (Beni, Lubomir)
  5. Other


Minutes

Participants: Eugene, Bill, Glenn, Dave, Chris, Beni, Simon, and Lubomir.

Other

At the beginning of the meeting Bill and Dave, representing also other non-physicists, expressed interest in learning more about drift chambers, GlueX detectors and physics and beyond. Eugene, Simon, Beni were happy to answer their questions. We all agreed also to organize a special presentation for them.

Production