From GlueXWiki
Jump to: navigation, search

August 22, 2013 FDC meeting


  1. Installation preparations [1]
    • Mechanical: infrastructure, survey, cooling system, AC
    • Electronics: crates, modules, LV, HV
    • Gas system
    • Controls: LV, HV, gas
    • Testing: cables, trigger, DAQ
  2. Engineering (Bill)
  3. Electronics (Chris, Nick)
  4. Tests at EEL126 (Beni)
  5. Other


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

Installation preparations

- We are done with the production and will continue discussing the installation. We went through the installation document linked above, where the installation topics are grouped in different categories, as in the agenda.

- Mechanical. Bill explained the way the detector rails will be installed: first in BCAL adjusting the two main rails to the nominal distance. Then the rails of the front installation cart will be adjusted and attached, and so on. The survey people will need space around the FDC and Bill was considering the possibility to remove the electronics racks. We think this should be done if absolutely necessary since the racks will be installed, powered, connected to ground, and this will delay the installation.

- Electronics. According to Nick and Chris, most likely the modules will be tested in the crates and then the crates with the modules together installed in the racks, as in the original plan. This worked already for the FCAL, they just had to remove the power supplies while installing the crates. The LV and HV system will be installed in advance before the start of the FDC installation. They will be needed for testing.

- Gas system. It's in production now. Some elements have been bought already. If the gas system is not ready when we start the installation, we will have to find a temporary solution: a dewar with Nitrogen, or better gas mixture.

- Controls. Some minimal control will be needed during the installation. Dave will work on the codes for the chiller, and the gas system.

- Testing. While connecting signal cables to the detector, we will test them by applying LV on the cards. For that we need the LV cables to be connected to the LV panels. After connecting all the cables to the detector we probably hav to disconnect the LV cables and re-route them, but this is to be seen. For the final testing we will use scintillators on the top and the bottom of the installation cart for triggering. We can try this in 126. Beni: for the DAQ there will be no problems to read 7 crates, what is needed for the test of one package.


- Bill is working on the attachment to support the mesh, that is needed to avoid the four extra rails.


- Half of the signal cables have been labeled by the students. In fact, the plan was to label them as we connect them, but as soon as they are sorted by labels this is OK. The other half of the cable we may leave unlabeled, or label and sort them if there's time and people to do this. As for the LV cables all they have to be labeled, so far 3/4 are done.

Tests at EEL126

- The FDC packages are being flushed with gas, all four bubbling at 100ccpm total. Next week we will do the final test just by applying HV to each package.

- We are testing now the spare package. Vlad did the grounding, signal and LV and HV connections to the top two cells. The max drift time for these cells is ~20usec and Beni made the corresponding corrections in the DAQ. He can read few thousand samples from the fADCs without a problem, but the event builder crashes above some event size when reading many modules.