Difference between revisions of "Minutes-10-7-2010"
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- Beni continued testing different gas mixtures (90/10, 85/15 and now 80/20) and showed some plots above. Pictures from the scope show after-pulses that are typical for these gas mixtures with high Ar content at high enough HV. Because of the after-pulses the ADC saturates. Fernando: where's the plateau? The end of the plateau is where the after-pulses start. The beginning has to be find by lower the HV, Beni covered so far ~150V for some of the mixtures. To reduce the after-pulses Beni wants to use the pre-mixed bottle Ar/CH4 95/5% and to mix it with CO2. Methane is flammable above 5% in air. Using methane in the hall has to be discussed, but first Lubomir will simulate it with Garfield | - Beni continued testing different gas mixtures (90/10, 85/15 and now 80/20) and showed some plots above. Pictures from the scope show after-pulses that are typical for these gas mixtures with high Ar content at high enough HV. Because of the after-pulses the ADC saturates. Fernando: where's the plateau? The end of the plateau is where the after-pulses start. The beginning has to be find by lower the HV, Beni covered so far ~150V for some of the mixtures. To reduce the after-pulses Beni wants to use the pre-mixed bottle Ar/CH4 95/5% and to mix it with CO2. Methane is flammable above 5% in air. Using methane in the hall has to be discussed, but first Lubomir will simulate it with Garfield | ||
to estimate the advantages. It is know that organic molecule cause polymerization on the wires at high rates and gains. The other halls (A and C) have been using ethane | to estimate the advantages. It is know that organic molecule cause polymerization on the wires at high rates and gains. The other halls (A and C) have been using ethane | ||
− | as quencher ( | + | as quencher (mixed with alcohol to prevent polymerization) for a long time. |
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Revision as of 16:45, 7 October 2010
October 7, 2010 FDC meeting
Tentative Agenda
- Production
- Blue Crab status
- Frame production
- Electronics
- Update on PCBs, fADC125 and other (Fernando, Chris, Gerard)
- Engineering
- Wire stringing: fixtures, movement system (Bill, David)
- Update on tension measurements (Lubomir)
- Wire tension requirements (Lubomir)
- Other: gas system using methane
- Full-scale prototype
- testing fADC125 (Beni)
- plateau studies with 80/20 (Beni)
- resolutions with different gas mixtures and HV (Lubomir) [FDC Log Book, pages 522,523]
- argon/CO2/methane gas mixture properties (Lubomir) [FDC Log Book, pages 523,525]
- MC studies with different gas mixtures (Simion) [FDC Log Book, page 521]
- Other
Minutes
Participants: Eugene, Fernando, Chris, Simon, Beni, Glenn, Gerard (on the phone), and Lubomir. Bill, David, and Casey were busy at 126 laminating the first wire frame.
Production
- There was a meeting between JLab people and AdvanceTEC that will build the clean room. Completion date: January 7th. AdvanceTEC had two concerns: the power coming to building (from Dominion Power) is close to the expected use and has to be checked. The second is related to the quality of the floor, not good enough for 10K clean room. AdvanceTEC will send a quote to re-seal the floor.
- Bill, David and a machinist from our machine shop visited "Vision machining". The frame production has started. About half of the spacer rings are ready. Two of the wire frames are here at JLab, being laminated in the moment with the Rohacell rings in 126. Five Rohacell rings were made by Casey and David. Tomorrow morning David with techs will be at Blue Crab to turn up two granite tables. The idea is to start using them for the lamination because of the limited space in 126.
Electronics
- Gerard will use the pulses generated from Garfield to study the timing of the fADC125 and will try different interpolation algorithms. He's working now on the firmware.
- Chris: all 28x4 boards were shipped to the company for stuffing and will have 2x4 (two of each type) ready within a week.
- Fernando will finalize the rigid-flex design (Roger is busy the next several weeks) and then submit it to the procurement. In a week (Oct. 14) we must here from the procurement about the cathode foils.