Difference between revisions of "Minutes-6-12-2014"

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FDC meeting ID: 290664653
 
FDC meeting ID: 290664653
 
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= Minutes =
 
= Minutes =
  
Participants: Curtis (CMU), Bill, Beni, Chris, Nick, Simon, Fernando, and Lubomir (JLab).
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Participants: Curtis (CMU), Bill, Beni, Dave, Eugene, Chris, Nick, Simon, Sergey Furletov, Fernando, and Lubomir (JLab).
  
 
== Gas system ==
 
== Gas system ==
  
- There were several problems in the FDC parts of the gas system. A series of graphs (from Mike) linked above demonstrate some of them. A 1 l/min leak was found due to bad fitting of one of the valves and later fixed: first graph shows the pressure in the mixing tank (red is FDC) with ~2 l/min filling flow and 0.4l/m FDC usage. To identify the place we were excluding different parts of the system. Once the tank was insulated (flat part in second graph) there was still some pressure drop; it turned out there's a small leak from the relief valve on top of the FDC mixing tank. Same valve is used on the CDC tank but it has not been checked. Narciso is looking for better valves.  
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- 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).  
  
- On Tuesday ~6pm there was again a failure of the FDC gas control box in the gas room. As a result the pressure in the mixing tank started dropping below 7 psi. We had to call the guard to open the room and reset the box. A new spare box has been ordered. For the future Beni suggests to have a key from the gas room in the counting house.
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- 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.
  
- Pressures in the six cells of package 1 are shown in third and fourth graph, when the flow was turned off and then on. It shows very small (~1Pa) variations probably due to temperature and very similar values in the different cells.
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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.  
  
- Mike has his first version of the gas GUI ready (screenshot linked above) and checked in the svn: https://halldsvn.jlab.org/repos/trunk/controls/css. Any remarks and recommendations are welcome and should be directed to Mike.
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== DAQ == 
  
== DAQ and CDC status == 
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- Beni got the DAQ working! Bryan Moffit helped him. It is working now with 4 CDC and one FDC crate. In the FDC crate in addition to the "slow" F1TDCs, Beni has also one fast F1TDC for the trigger scintillators.
  
- No news here. DAQ is in the Sasha's hands now.
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- Beni's plans: taking data with the CDC and setting the readout window, then doing the same with the FDC, then increasing the number of the crates.
  
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== Engineering ==
 
== Engineering ==
  

Revision as of 17:15, 12 June 2014

June 12, 2014 FDC+CDC meeting

Agenda

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

Instructions for Bluejeans meeting connection

FDC meeting ID: 290664653

Minutes

Participants: Curtis (CMU), Bill, Beni, Dave, Eugene, Chris, Nick, Simon, Sergey Furletov, Fernando, and Lubomir (JLab).

Gas system

- 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).

- 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.

- 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.

DAQ

- Beni got the DAQ working! Bryan Moffit helped him. It is working now with 4 CDC and one FDC crate. In the FDC crate in addition to the "slow" F1TDCs, Beni has also one fast F1TDC for the trigger scintillators.

- Beni's plans: taking data with the CDC and setting the readout window, then doing the same with the FDC, then increasing the number of the crates.