Difference between revisions of "Minutes-4-30-2015"

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= Minutes =
 
= Minutes =
  
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Participants: Curtis (CMU), Sean (NU), Luke, Fernando, Mike, Dave, Chris, Nick, Beni, Simon, Eugene, and Lubomir (JLab).  
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Participants: Curtis (CMU), Sean (NU), Luke, Fernando, Mike, Dave, Chris, Nick, Beni, Simon, Eugene, and Lubomir (JLab). Short meeting during the last week of the spring 2015 run.
  
 
== Collaboration meeting talks ==
 
== Collaboration meeting talks ==
  
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- Everybody at the meeting agreed with the agenda for the collaboration meeting. Last days, the sensor was connected to the first FDC package. It is strange that we see now about 59% CO2
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- Everybody at the meeting agreed with the agenda for the collaboration meeting.
  
 
== Gas puzzle ==
 
== Gas puzzle ==
  
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- Last CO2 results linked above  
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- Last CO2 results linked above.  Last days, the sensor was connected to the first FDC package. It is strange that we see now about 59% CO2, while before it was ~55%. The only change we did intentionally is the change of the CO2 gas factor from 0.77 to 0.74, which would correspond to 55->56% change of the CO2.
  
 
== CDC update ==
 
== CDC update ==
  
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- Mike is working on a code for the CDC alignment using Millepede package. This package has been successfully used in many experiments for tracking alignment including the big LHC experiments.  
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- Mike: CDC is working fine. One HV channel (G14) is not stable, most likely problem in the CAEN module.
  
 
== FDC update ==
 
== FDC update ==
  
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- Now using tracking through all the packages Lubomir studied the old problem: the deviation of the cathode-reconstructed  from the nominal wire position exhibits an interference pattern as function of x-coordinate (perpendicular to the wires) with deviations up to +/-200 microns. The question is whether the deviations are coming from the wire position offsets or somehow from the cathode reconstruction. For that we use a third point: the expected hit position from a track reconstructed from the outer packages.
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- First look at the FDC efficiency now with 6.3V threshold on the discriminators. Compared to the 8V thresholds before we see just a little increase of the efficiency from 94 to about 95%: not significant; could be also noise.
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For comparison, in the above three plots we use the same events and hits that are coming from the best tracks. The plots show the following mean deviations as function of x: cathode reconstructed - nominal wire position (first plot),  cathode reconstructed - expected hit position (second), wire reconstructed - expected hit position (third plot); all plots fitted with sine function plus linear term. One can see similar amplitude and frequency for the first two plots, while the last one is almost linear. It means that most likely the deviations are coming from the cathode reconstruction. However, the statistics is low and one could hardly expect much more from this spring run. Therefore the plan is to scan the spare package with a source.  
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== Electronics ==
 
== Electronics ==

Revision as of 11:34, 5 May 2015

April 16, 2015 FDC+CDC meeting

Connection

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

Agenda

  1. Collaboration meeting talks (meeting page)
  2. Gas puzzle
    • CO2 monitoring [2]
  3. CDC update (Beni, Mike)
  4. FDC update (Lubomir)
  5. Electronics (Fernando, Cody, Chris, Nick)
  6. Engineering
  7. Other


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