Difference between revisions of "Minutes-8-21-2014"

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Participants: Curtis, Naomi (CMU), Sean (NU), Beni, Mike, Luke, Eugene, Chris, Nick, Dave, Bill, Fernando, Sergey, Vlad and Lubomir (JLab).
 
Participants: Curtis, Naomi (CMU), Sean (NU), Beni, Mike, Luke, Eugene, Chris, Nick, Dave, Bill, Fernando, Sergey, Vlad and Lubomir (JLab).
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== DAQ ==
 
== DAQ ==
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- Lubomir: by applying timing cuts on the hits from the two cathodes and the wires in a cell, one can reduce the threshold down to 50 fADC units (~4mV). As a result we see now most of the "missing" cathode channels, that have problems with the conductive tape. Of course the resolution will be deteriorated but one can stiil use this information for the pattern recongition. Couple of interesting events are linked above.
 
- Lubomir: by applying timing cuts on the hits from the two cathodes and the wires in a cell, one can reduce the threshold down to 50 fADC units (~4mV). As a result we see now most of the "missing" cathode channels, that have problems with the conductive tape. Of course the resolution will be deteriorated but one can stiil use this information for the pattern recongition. Couple of interesting events are linked above.
  
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== Engineering ==
 
== Engineering ==
  
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- On Monday when the chiller failed, Wesley Moore was working on the epics communication with the device. According to Hovanes he changed the set temperature to a lower value for as short time, then the chiller failed. The plan is just to read the epics variables, and not to write anything to the device.   
 
- On Monday when the chiller failed, Wesley Moore was working on the epics communication with the device. According to Hovanes he changed the set temperature to a lower value for as short time, then the chiller failed. The plan is just to read the epics variables, and not to write anything to the device.   
  
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- Luke: we installed the encoder and started measurements at the last position, but in the middle the encoder stopped working. In addition motor got disconnected from the stage; the set screw got lose.
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- Luke: we installed the encoder and started measurements at the last position, but in the middle the encoder stopped working. In addition motor got disconnected from the stage. After the meeting the motor was fixed but there were still problems with the encoder. Luke will continue with measuremenst at two positions. The data with the encoder is enough to compare the two measurement methods.
  
 
== Commissioning ==
 
== Commissioning ==
  
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- We discussed briefly what is the trigger we want to use with the target placed ~4m upstream. In this case the BCAL geometrical acceptance is reduced significantly: ~7-14deg compared to >10deg for the nominal target position. Therefore, including the BCAL in the trigger will select mostly events originating from the nominal target. Curtis: the pions are mostly in the forward direction and this may not be an issue. In any case we need simulations and Simon already started doing them.  
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- Curtis presented a plan for the CDC commissionong linked above. When aligning the photon beam several inner HVBs will be supllied by Bertan modules so that one can see the currents which may help in the beam alignment. Then the plan is to have some initial data with magnet on for a short time, then for a longer time with the magnet off, and then (if time permits) with the magnet on again. They are concerned that the timing algorithm on the fADC125 may not be ready for the run. Eugene: while working on the photon beam the magnet will stay at 300A wich is safe.  
  
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-Curtis: According to Eugene, there will probably be minimal choice in the trigger. At best, we will be able
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- As Bill proposed on the last meeting it will be good to survey the FDC without magnetic field (planned already for September) and then to monitor one of the reflector while the magnet goes up. Eugene: the best would be to rump up the magnet when the Hall is opened in September and at the same time the survey can be done.
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to control the relative fraction of BCAL and FCAl energy.
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- Everybody agrees we better align the chambers without any magnetic field. If the trigger rate is too high an option will be to mask the inner FCAL blocks.
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== Other ==
  
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- Bill proposed to survey the FDC (the 16 reflectors visible from downstream) next week when the magnet will be set to 1200A.
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- Beni: Scot put alcohol in the bublers, we will monitor the chamber behaivior.
  
 
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Revision as of 20:14, 21 August 2014

August 21, 2014 FDC+CDC meeting

Agenda

  1. DAQ (Beni)
  2. CDC status Curved Tracks (Mike, Beni)
  3. FDC status scattering event, horizontal shower event (Lubomir)
  4. Electronics (Chris, Nick)
  5. Engineering (Bill)
    • Chiller
    • Cathode scan (Luke)
  6. Commissioning Wiki Page, CDC, FDC commissioning plan (all)
  7. Other

Instructions for Bluejeans meeting connection

FDC meeting ID: 290664653

Minutes

Participants: Curtis, Naomi (CMU), Sean (NU), Beni, Mike, Luke, Eugene, Chris, Nick, Dave, Bill, Fernando, Sergey, Vlad and Lubomir (JLab).


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