Difference between revisions of "Minutes-7-5-2012"
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== Engineering update == | == Engineering update == | ||
| − | - | + | - Bil gave us some detail about the cooling system: ~2gal, 32psi, tubes outside of the packages are (special) plastic 3/4" ID, brass compression fittings, manifolds are made out of Norel, tubes on the packages are copper 2.79mm ID. Water or Fluorinert: Fluorinert is $500/gal but volume is only 2 gal; the main concern is about leakages and special pump and fittings that are needed. Water leaks can cause damages, need to cover BCAL and try somehow to put the cover manifolds. It turned out at the LHC experiments there's only one example when water is used for detector that is not accessible: the ECAL for CMS, but in this case many additional systems are included (see text above) to monitor the pressure, temperature and flow and in case of leakage to separate sections of the system and evacuate the water from there. All at the meeting, including Bill and Eugene think Fluorinert is a better choice. |
| − | - | + | - Bill went through the drawings linked above, explaining the cooling system. |
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== Electronics update == | == Electronics update == | ||
Revision as of 18:06, 5 July 2012
July 5, 2012 FDC meeting
Agenda
- Production Construction Tracking (Dave)
- Production status
- Fourth package tests
- Refurbishment preparations
- Engineering update
- Cooling system [1], [2], [3],[4]
- Example of water cooling
- Electronics update (Chris)
- LV cable assignment (Vlad)
- Test set-up in 126 (Beni)
- Other
Minutes
Participants: Bill, Glen, Eugene, Chris, Nick, Simon, Vlad, Beni, and Lubomir
Production
- Dave was absent but he updated the production tracking linked above: last two spare cathodes are almost ready. Spare wire frames: third wire frame (#6) is being tested already for a week, the current is very high (~1100nA) which doesn't surprise anybody since the caps were not replaced. Bill wanted to know if we have to order additional g10 frames. We have one spare frame now that will be used to replace wire frame #1. First we will try to fix #6, if it doesn't work we have to order g10 frames. The problem with #6 is that the caps are covered with Himiseal. Bill suggested, first, removing the caps (say on one HV sector) and then cleaning the Humiseal. Chirs: aceton cleans Humiseal very well (we can't use it inside the chamber!), but one can also use alcohol; have to soak the Humiseal first and after 5min start cleaning. We will try that.
- Started preparations of the first package (which is at Blue Crab) for refurbishment: HV cables were disconnected from the cables connected to the two HV connectors. Later we may have problems to reconnect them since the cables were cut to the proper length, we have to route them exactly in the same way. Copper tubes (together with the one part of the pre-amp brackets that is glued to the tube) and the pre-amps were removed from the package.
- Fourth package tests: Vlad tested cell #4 which is OK. On cell #3 (with wire frame #27) the current was very high (~800-1000nA) and doesn't go down already four days, but never tripped: most likely the HV caps have problems. Other than that all the channels on #3 are fine. Vlad applied today HV on cell #2 (wire frame #28), the current was initially 500nA but then started going up. It turned out Anatoly doesn't have a record that he had replaced the HV caps on #28. We will finished with he tests on cell #2 and cell #1 and then decide what exactly we want to disassemble.
![[1]](http://www.jlab.org/Hall-D/detector/fdc/drawings/Assembly1.png){kind=link}
![[2]](http://www.jlab.org/Hall-D/detector/fdc/drawings/Assembly2.png){kind=link}
![[3]](http://www.jlab.org/Hall-D/detector/fdc/drawings/Assembly3.png){kind=link}
![[4]](http://www.jlab.org/Hall-D/detector/fdc/drawings/Assembly4.png){kind=link}