Minutes-10-25-2012
October 25, 2012 FDC meeting
Contents
Agenda
- Production Construction Tracking (Dave)
- Corrosion tests (Vlad)
- Engineering (Bill)
- Electronics (Chris, Nick)
- Third package tests FDC E-log (Lubomir)
- Other
Minutes
Participants: Eugene, Bill, Dave, Chris, Nick, Vlad, Simon, and Lubomir.
Production
- Dave deadened wire plane #29. Casey and Tina may come next Saturday to string wire plane #30. Will have the gas on Monday, hopefully by the end of the week will start testing the first package. Anatoly is refurbishing the cathodes for package #2. He removed the foil on four cathodes and started the fifth. We decided to stop the refurbishment until we are sure we have the foils. The foils are supposed to be here at the end of November.
- Bill: do we need first article for the foils to check if there are problems. Since this is the same company (Allflex) they know how to do them and what do we need. We didn't have problems with the foils before, Anatoly tested all of them strip by strip. Initially there was some discoloration on the copper and some wrinkles from the wheels of the machine, but they fixed the problems. Lubomir will discuss this with Roger, in case they see some problem to inform us. Eugene: we can use 5um foil, it will work except it will be thicker.
Cathode corrosion
- One more sample failed (possibly "Viton only") after 12 days exposure. The first one failed after 4 days (EPDM most likely). Will wait four weeks in total then will lower the temperature. Bill and Eugene are surprised that Apiezon "evaporates" at 100degC. In this case Viton and Viton+Apiezon samples at this high temperature must be similar, but actually there still might be some residue from the Apiezon, even it's not greasy. In any case such experiment will give you only a lower limit because: 1) Apiezon is different at 100degC 2) humidity is 100%.
Engineering
- Bill found a better colling unit (SMC), that compared to the old one (Trillium) has several advantages: it's new (not refurbished like Trillium), SMC monitors the return line as well so can identify leakage, and has RS-454 standard, and more energy efficient. Bill wants to order the SMC unit. Some additional stuff (flowmeters, bypass of the gear pump) still needs to be added to the system.
- Bill is ordering different materials for the fiducials, package spacers. Waitiing for the Norel manifolds to be able to install the cooling system on the packages.
- Cooling in 126: Bill discussed the problem with Tim and Ron Bartek. The max power in 126 is expected to be ~20kW, several options have been discussed ranging in $20-60k. The paradox is that the problem is not the cooling, but the heating! When it's cold outside the heater starts working and we can't stop it because it's used by several other "cold" areas. Most likely fixing it will take months and money. With the shift in the weather it will be dangerous to keep the chambers in 126. We discussed different options to move the testing set-up: the best would be to move it to Blue Crab. Questions: do we have enough power there, other limitations like using sources, internet speed, DAQ subnet. Bill: it will take time and efforts to move but in the long run it will be an advantage.
Electronics
- Chris: Daughter cards shipped for population, will have them ready next week.
Third package tests
- Beni made the software for testing the cathodes and tested three cells over the weekend (Elog #93). Lubomir and Vlad finished the other three cells (Elog #94). In total there were problems with four channels, but all were fixed by pushing the cards and bending the tubes. Now all the cathode and wire channels are tested and are working fine.
- We want to take the package out of 126 as soon as possible, but still need to look at the wire resolution. Beni's results so far show ~500 um resolution, way above the prototype resolution. He uses angles from the Indiana chambers (~1mrad resolution) and assumes the wires of the three pairs (1 and 4, 2 and 5, 3 and 6) are parallel. The difference is that now the wires are 6cm apart instead of 2cm in the prototype. Simon can reconstruct the tracks using hddm data from the cosmic tests. Looking at the residuals one should be able to estimate the resolution.
