Minutes-8-11-2011

August 11, 2011 FDC meeting

Agenda

1. Production Construction Tracking (Dave)
   • Status
   • Wire deadening
   • Other: Humi-seal, silver epoxy overheating
2. Engineering (Bill)
   • Update
   • Package flatness
3. Electronics (Chris)
   • Update
   • Pre-amp card connectors
4. Chamber testing at EEL126
   • Cell#2 status
5. Other

Minutes

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

Production

- Dave (see link above): all wire frames for the first package were laminated. Wire plane #5 ( the first to go in the package) will be populated tomorrow by Chris, followed by putting Humi-seal on the caps, and then wire deadening. Techs are working also on cathodes for cell#6: cathode type 1 is ready and the foils for type 2 are being cut.

- Wire deadening: the wire deadening of the first production chamber (wire plane #2) was successful. The thickness of one sample was measured by a microscope from Olympus company and they found it ~66 microns along one wire. The surface looked very good. We have permission to use the W&M microscope to check samples. Bill is going to look at different wires to make sure the tickness is the same.

- The chamber from 126 with cell#1 was moved to Blue Crab and the wire plane #1 was replaced with wire plane #2. All the cathode channels were tested with the testing card. We found that several daughter card connectors didn't make good contact at some channels. After re-connection (sometimes several) finally we got them working. One bad connection was found between the flex at the cathode (the first one of this kind!) and it was fixed after re-heating/pressing without changing the conductive tape. We found also on the top cathode at an area that was exposed directly to the AC blower in 126, that the silver epoxy got some brownish color. It turned out that 9 days ago after a thunderstorm overnight the AC in the EEL switched from cooling to heating and the temperature in the morning reached 95deg F. The Ac was fixed by 10am. It is not clear if it was the heat or humidity that caused this discoloration. We will prototype it, but the resistivity at this place was still low.

- Bill wants to try on one end window to use scotch-weld for gluing the thick mylar, he is afraid of the bubbles that appeared somewhere on the end windows.