Minutes-9-20-2012

September 20, 2012 FDC meeting

Agenda

1. Production Construction Tracking (Dave)
2. Cathode corrosion (Lubomir, Vlad)
   • Cathode protection tests
   • Recent SEM results [1], [2], [3], [4]
3. Engineering (Bill)
4. Electronics (Chris, Nick)
5. Third package tests FDC E-log (Beni, Lubomir)
6. TDR, pages 132-143 (Lubomir)
7. Other

Minutes

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

Production

- Dave: we started working on two new cathodes, #72 and #73, using the last two sets of foils (new foils are coming November/December). Casey and Tina finished stringing today the new wire frame #29. There was a small delay with the new g10 wire frames (Vision Machine didn't have the vacuum pump), but they promised to have the first frame by Monday.

- The first three cells of package #1 were assembled Monday-Tuesday using the standard Viton+Apiezon technique. Since then it's being flushed with gas. Oxygen goes down very fast, now it's about 1000ppm and expect it to be ~300ppm tomorrow so Vlad will start testing the package.

Cathode corrosion

- We tried several techniques for covering the cathodes but all they had some problems:

1. Kapton film + Hysol: many wrinkles, bubbles. Bill said he could do this using vacuum bagging, but should be done before the foils are stretched on the frame.
2. Kapton film + Apiezon: the O-ring made a channel into the grease and the surface outside of that channel was elevated due to the grease covered with the film. The O-ring compression was low, several leaks were found especially between the films. Still the oxygen went down to 75ppm for a cell with a cathode half covered with this method.
3. Hysol only: the epoxy layer that was applied was too thin (~0.5mil) so that it doesn't protect the copper efficiently. That was tested in the vacuum chamber were we saw copper discoloration with the Vition+Apiezon+Hysol sample, similar the the sample without Hysol.

- Vlad