Minutes-11-8-2012

November 8, 2012 FDC meeting

Agenda

1. Production Construction Tracking (Dave)
   • First package testing (Vlad)
2. Corrosion tests, corroded solder on Viton sample (Vlad)
3. Engineering (Bill)
   • Bubbler issue and pressure control [1]
4. Electronics (Chris, Nick)
5. Third package tests FDC E-log (Beni, Simon)
   • Moving to Blue Crab?
6. Other

Minutes

Participants: Bill, Dave, Chris, Nick, Vlad, Simon, Beni, and Lubomir.

Production

- Casey and Tina strung wire frame #30 on Saturday. Dave put the Kapton dots and did position measurements. Casey will come again this Saturday to glue the wires. Anatoly is preparing the old cathode frames for package #2 and will finish soon.

- Vlad is testing package #1. Currents on cell #4 300nA, #3 350nA, #2 170nA, #1 (just started) 500nA. For comparison 3 weeks ago we had 900nA on cell #4. All the channels so far are working fine. Vlad found two pre-amps oscillating.

Cathode corrosion test

- The testing chamber was opened.

Engineering

- Bill has ordered some parts for the cooling system and is working on the documentation for the rest.

- Bill is in contact with Ron Bartek and Paul Powers about possible solutions for the cooling of 126. After the meeting Walt Akers came with a solution to install three ceiling fans to blow the hot air to the high bay (target) area using flexible ducts. Cooler air from the high bay will be drawn through a louver that will be mounted at ground level.

Electronics

- Chris: Daughter cards shipped for population last week, company confirmed that all is ok, will have them ready next week.

Third package tests

- Beni has now a software to convert the evio data files to hddm including fADC information. We had special runs with cathode information (both up/down) from three cells. Simon will look into this. At the same time Simon looked into the runs with wire information only and found an estimate for the resolution (at the minimum, as function of the distance to the wire) of ~200 microns. Eugene: since Simon included all the wires in the fit and we have two degrees of freedom, the resolution must be factor of sqrt(2) bigger, maybe consistent with Beni's result when using parallel wires.

- Eugene started a discussion that we need to include the angles measured from the external chambers, into the hddm file. Simon proposed a way to do you: treating the external chambers as other FDC packages.

- In all the runs last week we see noise on wires in cell #1 and #2, while the noise in cell #3 disappeared (Eugene: the law of noise conservation). Also, somehow we don't see good signals in the fADC from the short strips in cell #3, while signals are OK when looking with a scope!? Cables, fADC channels were tested at other places and work fine. We will continue investigating these problems.

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