Difference between revisions of "Minutes-9-13-2012"
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- We will wait till Monday to see the final oxygen percentage and will open the test package. If everything is OK we want to use the Hysol technique for the first half of the first package. Bill wanted to know if Dave is happy with the Hysol coating, then they discuss how to improve the flatness of the Hysol layer. In any case we will practice more before working on the production cathodes. Bill also proposed to use conformal coating instead of Hysol, but Eugene and Lubomir didn't agree since it introduces new material and there are complains from drift chamber groups about possible out-gassing of the conformal coating. Even we have some parts of the PCBs coated inside the gas volume and we try to find the same material, we still need to do long tests | - We will wait till Monday to see the final oxygen percentage and will open the test package. If everything is OK we want to use the Hysol technique for the first half of the first package. Bill wanted to know if Dave is happy with the Hysol coating, then they discuss how to improve the flatness of the Hysol layer. In any case we will practice more before working on the production cathodes. Bill also proposed to use conformal coating instead of Hysol, but Eugene and Lubomir didn't agree since it introduces new material and there are complains from drift chamber groups about possible out-gassing of the conformal coating. Even we have some parts of the PCBs coated inside the gas volume and we try to find the same material, we still need to do long tests | ||
| − | before we are sure it will not harm the chambers. | + | before we are sure it will not harm the chambers. As for the other technique, using Apiezon on big areas is messy and not possible to clean, it may start leaking at higher temperature when chamber is in vertical position? |
- Vlad started a new test in the vacuum chamber now adding a sample with Viton+Apiezon against cathode foil that was coated with Hysol. The chamber will stay at very high temperature (close to 100deg C) and 100% humidity till Monday. | - Vlad started a new test in the vacuum chamber now adding a sample with Viton+Apiezon against cathode foil that was coated with Hysol. The chamber will stay at very high temperature (close to 100deg C) and 100% humidity till Monday. | ||
| − | + | ||
== Engineering == | == Engineering == | ||
Revision as of 18:49, 13 September 2012
September 13, 2012 FDC meeting
Contents
Agenda
- Production Construction Tracking (Dave)
- Cathode corrosion
- Recent tests
- Engineering (Bill)
- Electronics (Chris, Nick)
- Third package tests FDC E-log (Beni)
- TDR, pages 132-145 (Lubomir)
- Other
Minutes
Participants: Eugene, Bill, Dave, Simon, Chris, Vlad, Beni, and Lubomir
Production
- Dave: 7 cathodes ready, another 5 need daughter cards to be glued. Will have 200 new cards (Lubomir) beginning of next month, we better use them for the rest of the cathodes; so far we have 3 cathodes with refurbished daughter cards. One new wire frame (#29) is ready for stringing, Anatoly just put HV caps and tested it. Adam (Vision Machine) will bring one g10 wire frame next Wednesday and another three on Friday. After Rohacell lamination Adam will fly cut it and we will have the first frame for the PCB lamination next Friday. Bill: Adam will need our de-humidifier.
- Lubomir: we may try to fix the wire frames #27 and #28 that are drawing high current. Suspect the via of the HV trace that connects the bottom trace just against the Rohacell. If this is the problem can be fixed by drilling a hole from the back side.
Cathode corrosion
- On Monday we started a test with a cathode (the demo one) using two techniques to protect the copper from corrosion: one side lightly coated with Hysol, the other with Kapton films sitting on Apiezon. We installed this cathode in a cell with Viton+Apiezon and started flushing with gas at 200ccpm (to have enough flow through the oxygen sensor). Some leakage was found (< 10^-4) at the Kapton side but that pressure inside is very high due to the higher flow rate per cell. Interestingly leakages were found at the two transition regions between the Kapto and Hysol areas, probably the Hysol layer is thicker than the Kapton film. Importantly, the oxygen went down to 180ppm.
- We will wait till Monday to see the final oxygen percentage and will open the test package. If everything is OK we want to use the Hysol technique for the first half of the first package. Bill wanted to know if Dave is happy with the Hysol coating, then they discuss how to improve the flatness of the Hysol layer. In any case we will practice more before working on the production cathodes. Bill also proposed to use conformal coating instead of Hysol, but Eugene and Lubomir didn't agree since it introduces new material and there are complains from drift chamber groups about possible out-gassing of the conformal coating. Even we have some parts of the PCBs coated inside the gas volume and we try to find the same material, we still need to do long tests before we are sure it will not harm the chambers. As for the other technique, using Apiezon on big areas is messy and not possible to clean, it may start leaking at higher temperature when chamber is in vertical position?
- Vlad started a new test in the vacuum chamber now adding a sample with Viton+Apiezon against cathode foil that was coated with Hysol. The chamber will stay at very high temperature (close to 100deg C) and 100% humidity till Monday.
