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October 22, 2015 Drift Chamber meeting


  1. Instructions for Bluejeans meeting connection
  2. Meeting ID: 290664653
  3. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.


  1. CDC update (Mike, Simon)
  2. FDC update (Luke, Lubomir)
  3. Electronics (Fernando, Chris, Nick)
  4. Engineering (Dave)
    • gas pressure variations [2], [3]
  5. Other


Participants: Naomi, Mike (CMU), Sean (NU), Fernando, Luke, Dave, Chris, Nick, Simon, and Lubomir (JLab).

CDC update

- Simon submitted changes reflecting the time-to-distance calculations. He uses Mike's table with the wire-tube offsets (as extracted with cosmics) to re-calculate the time-to-distance function (with field off and on), as he reported last week. Mike is checking the new calculations for curved tracks.

FDC update

- Lubomir almost finished converting his code with specialized FDC alignment/efficiency calculations into a plugin that runs with the standard halld analyzer. One important difference is that the multi-hit feature present in the original code could not be preserved in the pluging - halld analyzer assumes only one hit per channel. Still the resolutions obtained with the plugin are very similar to those with the original code. Some tweaks had to be made in the emulation code, as well. The plugin produces 3D hits (points) using both cathode (amplitude) and wire (timing) information. We will work on an interface that passes these points to Simon's tracking.


- Dave: the NBX serial issue is still there, even he tried to to put all kind of possible software fixes. Next step would be to replace the hardware - the NBX module and the MFC control box.

- Lubomir showed plots with correlation b/n the variations in the temperature in one of the BCAL crates (up to +/-4degC) and the FDC pressure (+/- 1Pa). These oscillations started over the weekend, when the humidity went below 30% the HVAC system stopped regulating it, but only the temperature.