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September 7, 2017 Drift Chamber meeting


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  2. Meeting ID: 290664653

Headline text

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  1. CDC
  2. FDC
  3. Tracking
  4. fADC125
  5. Other


Participants:Naomi, Alex B., Dr. Mike Staib (CMU) Alexander A., Beni, Simon, Sergey, and Lubomir (JLab).


- Discussing the plot Naomi showed yesterday on the analysis meeting - in MC, CDC efficiency going slightly down for the outer layers. Simon explains it with the tracking: when you "swim" you start from the inner ring and the multiple scattering is not taken into account (unlike the tracking itself).

- Naomi discussed with Beni what should be put in the CCDB for the CDC threshold.

- We discussed if it is worth using "FDC amplitude" mode 9 for the CDC readout. Naomi already demonstrated the advantage of using the pulse height of the first peak, instead of the integral for the dE/dx. Sergey explains the fact that most of information is in the first peak by space charge effects, that were seen in the theta dependence of the dE/dx. If the DAQ permits it is worth having information for two peaks (NPK parameter in the firmware =2). All this requires testing


- Simon is working on better treatment of the big drift times in the FDC that create the 30 deg structure Alex A. has observed also in MC.


- Naomi got from Cody the firmware for self-triggering and will test it. Any channel above the threshold generates the trigger.


- Some issues with the gas system that happened when there was no CO2 supply have to be understood. The gas supply to the FDC mixing tank was bigger than the gas usage by the FDC. Beni performed a test and no leak was found between the mixing tank and the FDC. The techs found leakage in the check valves that were used just in this case to separate the empty gas bottles.

- Next meeting in three weeks.