Minutes-6-30-2011

June 30, 2011 FDC meeting

Agenda

1. Production (Dave)
   • Status Construction Tracking
   • Second cell HV tests
   • Radioactive source usage at Blue Crab
   • Other
2. Engineering (Bill)
   • Package flatness measurements
   • FDC cabling
   • Other: gusset rings, lifting frame
3. Electronics update (Fernando, Chris)
4. Chamber testing at EEL126 (Beni, Lubomir)
   • First cell status top/bottom asymmetry
   • Future plans
5. Other

Minutes

Participants: Eugene, Bill, Dave, Chris, Mark, Roger, Simon, Beni, and Lubomir.

Production

- Dave (see the Construction Tracking link above): cell#3: cathode type-2 needs three rigid-flexes (they were glued but Casey found they had solder bridges on the connectors), cathode type-1: the rigid-flexes to be glued. Since Monday we stopped working on the wire frame that was strung, due to possible tension problems discussed later. cell#4: first cathode tensioned, gluing foils for the second one. In addition techs are laminating wire frames, 6 ready so far. Beni asked if we cover the wires while soldering; not yet but we have the cover ready and will try it for the next wire plane. So far we have seen one solder ball on the wires, and Casey removed it.

- Lubomir on second cell HV tests: the cell is assebled as a package, now with lexan sheet on the top. The gas is runinng since Tuesday evening and since Wednesday we are conditing the chamber. Today we are at 1800V/-500V with a current of 120-130nA for the whole chamber, which is at least 10 times smaller than the first cell. So, most likely the HV problems we had with the first cell are due to the ultrasonic cleaning in water (which doesn't surprise anybody).