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November 1, 2012 FDC meeting


  1. Production Construction Tracking (Dave)
  2. Corrosion tests (Vlad)
  3. Engineering (Bill)
    • 126 cooling
  4. Electronics (Chris, Nick)
  5. Third package tests FDC E-log (Beni, Simon)
    • Moving to Blue Crab?
  6. Other


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


- Casey and Tina will come this Saturday to string wire frame #30. Dave will then work on it. This is the last frame we need for package #4, but will make two more spare wire frames. Answering Eugene's question: we will have to make four more cathodes to finish with the package production, but eight more cathodes will be done as spares.

- The gas (40/60) will be delivered to Blue Crab next Wednesday. In the mean time we found a 40/60 gas bottle delivered by mistake to JLab. We already started using it for the package #3 tests, since we didn't have Ar. Nevertheless, we decided to take it from JLab and use it at Blue Crab to start testing package #1. We expect to have Ar bottle soon, to be used at JLab.

Cathode corrosion test

- No news, the lower limit now for the time before corrosion is 1-3 years, depending on the activation energy. We will continue with the tests till Monday, then will open the chamber and prepare another set of samples to be tested at lower (65degC) temperature. This will give us an estimate of the activation energy, expecting the result within a month.


- 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.


- 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.