Difference between revisions of "Minutes-5-19-2011"

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- On one end window the epoxy didn't cure, but a sample from the same epoxy (and the left part in the cup) did cure. We suspect the surface was contaminated. Eugene: it's possible the epoxy was not mixed good enough. Also the surface on the end window is the only surface on the g10 frames that is not machined, and it is very smooth. On the second end window done in the same way the epoxy cured better. Most likely it was a contamination problem: we cleaned better the second end window. For the future production we will sand the surface of the frame.   
 
- On one end window the epoxy didn't cure, but a sample from the same epoxy (and the left part in the cup) did cure. We suspect the surface was contaminated. Eugene: it's possible the epoxy was not mixed good enough. Also the surface on the end window is the only surface on the g10 frames that is not machined, and it is very smooth. On the second end window done in the same way the epoxy cured better. Most likely it was a contamination problem: we cleaned better the second end window. For the future production we will sand the surface of the frame.   
  
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- Two wires were broken on the first production frame while removing it from the strong-back. Bill will make a tool that separates the frame from the strong-back. The encoder on the motion stage doesn't work and most likely it is the bulb on the encoder head to be blamed. It is an old model, so if we need an encoder we have the replace the whole device. For the first production chamber  The pin rail was taken for fixing at Vision Machine and we expect it back hopefully later this evening. After that we can fix the two wires.  
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- Two wires were broken on the first production frame while removing it from the strong-back. Bill will make a tool that separates the frame from the strong-back. The encoder on the motion stage doesn't work and most likely it is the bulb on the encoder head to be blamed. It is an old model, so if we need an encoder we have the replace the whole device. For the first production wire frame we didn't use the encoder; the stepper motor resolution was good enough. The pin rail is now at Vision Machine for fixing and hopefully will be back later today. After that we can fix the two wires.
  
 
== Engineering ==
 
== Engineering ==
  
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- Bill: problem with one machine at "Vision Machine" and that's why we are still waiting for the ring needed to tension the end windows and for the jig plate needed for the chamber assembly. Hopefully we will have these at the beginning of next week. The parts for the ultrasonic cleaner and the tool to tape the wires (with Kapton dots) are in the machine shop. Finally we have the four penetrations in the clean room done. We don't have to vent the gas out of the clean room, so the bubbler for the tests will be inside. 
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- The vibrations at Blue Crab were investigated on Saturday by Kirk Davis. He used an accelerometer connected with an analyzer and measured the vibration frequencies at different places (see the above link). On the sensor (also table, strong-back) he observed the same frequency (~39Hz) as on the AC unit and on the supporting beam, also on the walls but not on the floor. So, most likely the source is the AC coupled to the stringing table acoustically.  
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- Tools and parts needed for the package assembly (and also for the first chamber testing): Bill prefers to have one gusset for one side of the package instead of many sectors, though it will be more expensive. The tooling will be similar to the one we used for the full-scale prototype, some parts (like the hubs) are now on the prototype, but Bill will make a second set so that one can be used for testing and the other for assembly. For the first chamber tests we will take the parts from the full-scale prototype. Eugene suggested not to disassemble the prototype so that we can do comparative tests if we have to. Therefore we will take only the hubs and replace the gussets with plastic ones.
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- After the meeting Bill, Dave and Lubomir went to 126 to discuss the procedure for the partial disassembling of the prototype. We decided that the best is to transport the prototype to Blue Crab and replace some of the parts needed for the first chamber assembly and testing. Such replacement will be done sector by sector so the prototype will be affected minimally. We need to take the hubs and some of the rods. This will happen beginning of the next week and we better use a van in which we put the chamber horizontally on a flat Lexan plate.
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== Electronics ==
 
== Electronics ==

Revision as of 23:57, 19 May 2011

May 19, 2011 FDC meeting

Agenda

  1. Production (Dave)
    • Cathodes
    • Wire planes
    • End windows: epoxy problem
  2. Engineering (Bill)
  3. Electronics status(Fernando, Chris)
  4. Chamber testing (Beni)
  5. Other


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