Difference between revisions of "Minutes-6-2-2011"

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= Minutes =
 
= Minutes =
  
Participants: Eugene, Bill, Dave, Chris, Simon, Beni, Caleb Massey (summer student) and Lubomir.
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Participants: Bill, Dave, Chris, Beni, Glenn and Lubomir.
  
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Short meeting since most of the people are at Blue Crab every day and know what's going on; still we discussed some issues in more detail. For the outside people I added more info about the current status.
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== Production ==
 
== Production ==
  
- Dave: HVAC didn't work starting Tuesday evening  (likely), and today Ron Bartek replaced a fuse in line with the transformer that failed before, but was replaced with a more powerful one. So, the same problem again; people from the clean room company will be there next week. Wednesday and Thursday morning the humidity was 50-60% and all the gluing was postponed.
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- The first stack is being assembled right now. We have, from bottom to top on the assembly fixture: 9 empty cathode frames, end window (1mil mylar) with O-ring, cathode type 3 (0.5mil mylar with holes on the bottom and cathode foil on the top). Casey is putting now the O-ring on the wire plane that will be installed in the package right after the meeting. Then we will put the spacer ring (also ready except for O-rings) and then will put on the top the transparent lexan sheet. Later we will replace it with the second cathode (ready) and the second end window.
  
- Cathodes: two ready, except gluing the daughter cards to the frame, that will be done today (conductive epoxy to the copper surface and Scotch-weld epoxy on the sides).  Third one is ready for gluing the rigid-flexes. The fourth has been tensioned and the frame glued. Fifth cathode foil is ready, as well. End window: Anatoly is finishing the first one.  
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- Cathodes: we have the third (type 3) and fourth (type 1) cathodes mechanically ready, waiting for the rigid-flexes, on the fifth cathode (type 3) the mylar will be tensioned today. By tomorrow  we will have also the second end window (2mil mylar) ready.  
  
- Wire frames: the two wires of the first wire frame were fixed. We will keep it on the table to study the sensor problem: today we had problems not only with the field wires, but also with the sense wires. Dave will coordinate with Ron Bartek how to turn off the AC units to study the vibration effects. Caleb will work on this problem. Eugene pointed out that before trying to mitigate the vibrations we have to make sure that they are the origin of the sensor problem.
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- Wire frames: the second wire frame is being prepared now for stringing. We have also the third wire frame laminated.  
  
 
== Engineering ==
 
== Engineering ==
  
- The second modification of the pin rail was successful. Results from CMM measurements of the front pin positions are shown at page 567; the width of the distribution is 10u (sigma).
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- Rigid-flex pressing tool: today Bill and Casey did tests using pressure indicator paper. It showed that the issues we had with the un-tinned  flexes are due to pressure not being equally applied on all the contacts. With the tinned contacts, due to increased thickness, the pressure was OK for all the test configurations. For the un-tinned contacts they tried several configurations: kapton tape only at one side of the connector (first two cathodes were done in such configuration), kapton tape over the connector, and without kapton tape. The best results were obtained with the kapton tape over the connector. In addition they tested 
New dowel pins were put on the rail to make sure the two parts of top plate can't move. Bill will install monuments on the table and strong-back that will help fixing wires. Today we had to align the strong-back so that the new replaced wires are parallel to the rest.
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- The new tool for gluing the rigid-flexes works reliably only with the tinned flexes. On the first two cathodes we used tinned ones, except at two places. Bill thinks it is the new foot that has to be modified to fix the problem, and will try to do it a.s.a.p. After that we will make again several samples and also work on the testing cathode to investigate the problem. Eugene insisted that before continuing with the production we have to make sure the tool works as before. All the samples that we investigate before were made with the old tool, that in principle we can also use but we had some problems with the foot attachment.   
 
- The new tool for gluing the rigid-flexes works reliably only with the tinned flexes. On the first two cathodes we used tinned ones, except at two places. Bill thinks it is the new foot that has to be modified to fix the problem, and will try to do it a.s.a.p. After that we will make again several samples and also work on the testing cathode to investigate the problem. Eugene insisted that before continuing with the production we have to make sure the tool works as before. All the samples that we investigate before were made with the old tool, that in principle we can also use but we had some problems with the foot attachment.   

Revision as of 15:40, 2 June 2011

June 2, 2011 FDC meeting

Agenda

  1. Production (Dave)
    • First chamber assembly
    • Cathodes
    • Wire planes
    • Other
  2. Engineering (Bill)
    • Rigid-flex gluing tool
    • Wire position measurements
    • Other
  3. Electronics update (Chris)
  4. Chamber testing (Beni)
  5. Other