Minutes-10-28-2010

October 21, 2010 FDC meeting

Tentative Agenda

1. Production (David)
   • Blue Crab status [ttp://www.jlab.org/Hall-D/detector/fdc/production/BCplan.pdf sketch]
   • Frame lamination FDC Log Book, page 533
2. Electronics (Fernando, Chris, Roger)
   • Update on PCBs
   • Cathode foil and rigid-flex procurement
   • fADC125/F1TDC synchronization (Beni, Gerard) FDC Log Book, page 531
3. Engineering (Bill, David)
   • Wire stringing
   • Cathode foils: plans for inspection, storage, and cathode lamination
4. Full-scale prototype tests (Lubomir)
   • gas gain measurements FDC Log Book, page 530
   • other studies with fADC FDC Log Book, page 532
5. Other

Minutes

Participants: Fernando, Eugene, Casey, Bill, Mark, David, Chris, Simon, Glenn, Roger, Beni, Gerard (on the phone) and Lubomir.

Production

- The humidity was very high yesterday (above 80%) at Blue Crab and the Rohacell material that was not laminated deformed. We still have to check if the four laminated wire frames that are at Blue Crab are OK. Bill: we can't stop the production and should continue with the lamination. Slution: to put a dehumidifier at one of the offices at Blue Crab and to use it for the Rohacell lamination. To recover the original Rohacell shape ones needs to heat it at 250degF, but don't have to do it because we have enough material (Casey).

- We will try to do both the Rohacell ring gluing and the lamination to the wire frame at once with vacuum bagging. Bill is thinking about a box for storage flushed with nitrogen. 14 wire frames (almost half) are laminated.

Electronics

- Chris was investigating different ways of cleaning the PCBs using Vigor flux-off. Bill asked if we can buy an ultrasonic cleaner 42"x18"x6" that will be used also to clean the wire frames after soldering the wires, for $5500. Glenn agreed.

- Fernando: the first article signal cables will arrive by mid November and Chris is working on a board to be used for testing. The solder material (japanese) recommended from UVA is no longer available. Chris ordered similar materialial from other company to exercise. Working on the sole source procurement of the ASICs. Fermilab is also intersted in the same ASICs and Fernando discussed if we can share with Fermilab the costs for the mask (~$100K).

- The contract for the cathode foils was awarded. Alflex is waiting for the Gerber files from Roger; the files are ready waiting final approval from Bill and Fernando. After that we will have the first article in three weeks, then we have one week (around Thanksgiving) to approve it before the start of the whole production.

- Rigid-flex: Roger is waiting for quotations from two companies after some additional explanation concerning the coating. Allflex already decided not to bid for this. Then Roger will submit a PR for 500 rigid-flexes. Once more we discussed the technique to be used for soldering to the cathode foils. Fernando prefers to use conventional soldering instead of using conductive film; the argument: the later technology exists for only 4 years and we are not sure if the soldering will work for 10 years. We will have plenty of material to exercise this and to measure the failure rate of the standard method and to try the new one. After that we should make a decision.