Difference between revisions of "Minutes-6-19-2014"

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== Electronics ==
 
== Electronics ==
  
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- Nick: three CDC HV modules replaced with the ones recently repaired and they are working fine. In the moment we have 2 spare 1550P modules and another 2 are being repaired in Italy
+
- Nick: three CDC HV modules replaced with the ones recently repaired and they are working fine. In the moment we have 2 spare 1550P modules and another 2 are being repaired in Italy. In addition, Fernando ordered two extra 1550Ps that will be delivered by September.
  
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== Gas system ==
+
- Two thermocouples have been installed on the CDC: one on the cooling duct and the other on the detector. Thus, one can check if the cooling is working. After some measurements it will be possible to interlock the CDC LV supply in case the cooling fails. 
  
−
- The new gas control box has arrived and yesterday Scott replaced the faulty one at the FDC mixing tank. When doing this Scott was following the settings in the procedure where the channels for CO2 and Ar are swapped. However, as it turned out after the meeting, he also followed the cables on the back of the box and swapped them too, in result the gas mixture didn't change (there was some confusion during the meeting). 
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== Gas system ==
  
−
- Several times during the past week the HV tripped both in FDC and CDC, and we think it could be correlated with the change of the atmospheric pressure. We need to measure, record and archive the absolute pressure since the gas properties scale as E/p (filed/pressure). Dave will look for solution.
+
- Leak test of the gas system has been performed by closing the mass flow controllers to the detectors first, then closing all the inputs and outputs of the two mixing tanks (pressure graph linked above). It showed a drop of ~1psi in four hours for the CDC tank and much less for the FDC tank. The sniffer showed a leakage on the CDC relief valve of ~10^-3 (from 10^-5 in air) and ~10^-4 on the FDC relief valve. Scott ordered relief valves with better quality from Circle Valve Technology Inc.
  
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- The rates of filling the FDC and CDC mixing tanks are very similar now but they are supposed to be 0.6 vs 0.8 l/min. We suspect some leakage, maybe in the relief valves. We are going to do some tests tomorrow with Scott to figure this out.  
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- We used this test to check the leaks in the FDC. The pressures in each cell of the four packages are linked above. The first two cells showed no measurable leak in 6 hours
  
 
== DAQ ==   
 
== DAQ ==   

Revision as of 17:18, 19 June 2014

June 19, 2014 FDC+CDC meeting

Agenda

  1. Gas system leakage test, [1], [2], [3], [4]
  2. DAQ (Beni)
  3. CDC status (Mike)
  4. Electronics (Chris, Nick)
  5. Readiness review (Beni, Lubomir)
  6. Engineering (Bill)
    • cathode measurements
  7. Other

Instructions for Bluejeans meeting connection

FDC meeting ID: 290664653


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