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

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- Dave: the set-up for gluing the rigid-flex assemblies is ready; today we will start gluing the assemblies on the first two production cathodes. The set-up was tested today with one flex glued then removed and then glued again. Two other cathode planes were glued, one of them tensioned and the frame glued on it.  
 
- Dave: the set-up for gluing the rigid-flex assemblies is ready; today we will start gluing the assemblies on the first two production cathodes. The set-up was tested today with one flex glued then removed and then glued again. Two other cathode planes were glued, one of them tensioned and the frame glued on it.  
  
- 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. The second  
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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. 
  
- Final results from the position and tension measurements of the first production chamber are shown at page 565 of the FDC logbook. We decided that we have to fix the offset in the pin position of the jig rail. From the position measurements (as explained at page 565) the pitch is short by ~130 microns. Dave measured it directly with a caliper and found ~100microns which is consistent, given the precision of the caliper and the fact that 130microns is the gap averaged over all the wires on both sides. Bill will bring the pin rail to the machine shop for fixing it and will try to expedite this since it stops the wire plane production. His idea is to increase the hole sizes so that one can vary the gap, to map the positions of all the pins and thus to adjust the gap, after that to put pins to fix the position. Tension measurements were done in a half a day, the voltage on the generator was kept 1V for both field and sense wires (before we used 3V for the sense wires). We found one sense wire broken between the solder pad and the glue; it was replaced by Casey. One of the filed wires had lower tension because of its weight touching the lower plate of the weight shielding. This most likely happened because the screw used to attach to the wire was not so tight and the weight slipped. Adding to the procedures: before gluing the wires one should open the shielding and check that all the weights are hanging.
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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 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.
  
 
== Engineering ==
 
== Engineering ==

Revision as of 23:27, 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