Minutes-6-7-2012
June 7, 2012 FDC meeting
Agenda
- Swiss schnaps (Beni)
- Production Construction Tracking (Dave)
- Production status
- Fourth package tests (Vlad)
- Engineering update (Bill)
- Electronics update (Chris)
- Gas system (Beni)
- Test set-up in 126 FDC E-log (Beni)
- Other
Minutes
Participants: Bill, Dave, Chris, Nick, Vlad, Beni, and Lubomir.
Production
- Dave: working on the last wire frame, Casey finished wire gluing. Chris will put elements on a wire frame tomorrow. Also two wire planes will be deadened tomorrow/Monday. Cathode #47 (type-2) had a problem on strip #1: there is a small bump of epoxy on the trace leading to the connector; it was put there before to fix small deformation of the Kapton foil. Since the bump was very close to the O-ring and solid g10 surfaces we were afraid that it may create gas leakage. After trying to remove part of the epoxy we damaged the copper trace. At this point we decided to put another cathode in the fourth package. Later the trace was fixed by applying conductive epoxy (3-4 Ohms strip to connector resistance) but we decided to use this cathode as a spare and make another cathode for the fourth package (#55) which will be ready by Wednesday-Thursday. Also by that time we will have all the wire frames ready to finish the fourth package.
- Dave predicts we will have all the elements, also the spares, done by the end of June. Then the work will be focused on the first and second package refurbishment. Related to that Bill asked when we can do full package tests in 126. Answer: everything depends on the fADC125 availability. We need to discuss this with Fernando since it will delay the FDC production/testing, and make a plan at least for partial testing of the cathodes using as many fADC125 as possible.
- Three cells were installed on the fourth package at the end of the last week. Vlad reported on the tests: oxygen went down to 77ppm, all channels were tested with scope/source and are working fine. However, on the top cell (#4) he found a point source of noise (~50kHz, high amplitude) visible on one wire (#21), top strip and bottom strip; most likely standard hair-on-wire problem. On cell #5 Vlad found that the current increased in one day from ~20nA to ~200nA and then it was stable. We will keep the HV on #5 and depending how stable it is we will decide if we want to open it as well, or open ONLY the top cell (#4) to fox the high frequency noise.
