Minutes-6-14-2012
June 14, 2012 FDC meeting
Contents
Agenda
- Production Construction Tracking (Dave)
- Production status
- Spare wire frames (Lubomir)
- Engineering update (Bill)
- Electronics update (Chris)
- Cable assignment and labeling (Vlad)
- Gas system (Beni)
- Test set-up in 126 (Beni)
- Other FDC E-log
Minutes
Participants: Caleb, Dave, Chris, Nick, Vlad, Simon, Beni, and Lubomir.
Production
- Dave: on last wire frame (#18) had to replace one sense wire and twice one field wire due to incorrect tension, now it's out of the string table and Chris will put the components tomorrow. Two wire frames will be deadened tomorrow, and #18 will be deadened on Monday. Cathode #55, the last for package #4, is ready too. On Tuesday/Wednesday we will continue with the stacking of the fourth package. Working on spare cathodes #54, 57, and 59.
- The problem with the noise on cell #4 was solved: a tiny piece of epoxy (or something like that) got stuck to the sense wire in that area. Casey cleaned it but that was not easy. The package was closed on Friday and this week was tested: the noise disappeared.
- Wire frame #1 can't be used at > 1900/-500V and at this voltage the current is very high (~1uA). Before the meeting Eugene agreed to purchase another 4 spare sets of PCBs. Therefore, before purchasing, we want to test a.s.a.p. wire plane #2, that has a conductive spot from the chemical used for deadening, shortening a field and sense wire. We will test also the other two spare wire planes, but they seam to be fine. Then we will know how many new wire planes we need to build. We have only one extra G10 wire frame and in case we need more we have to order them, as well.
Engineering update
- Caleb: Bill is busy, but he explained very well details of the outer (outside of the FDC) part of the cooling system that will have Fluorinert and water loops. Caleb will work with Bill also on the testing of the cooling system.
Electronics update
- Chris: LV cables have come
Gas system
- Beni is in contact with Narciso Gomez about the gas system. We discussed if we would need to filter the water that according to the gas company would be less than 200ppm in the CO2 bottles. Lubomir: don't have to filter since 200ppm is low enough especially when the oxygen level is low. Beni was advised to contact the GTS gas company since JLab has a contract with it.
Test set-up at 126
- Vlad will start testing all the cathode channels of the first package with a source and scope. We want to see if there was some deterioration of the cathode connections done with the z-axis conductive tape. There are some indications for increased resistance (up to 5-6 Ohms) on a small percentage of cathode channels, about 3-4 channels per cathode, at Blue Crab. This, however, could be due to handling of the cathodes and once they are installed in a package there's no deterioration.
