Difference between revisions of "Meeting-9-7-2017"

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August 10, 2017 Drift Chamber meeting
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September 7, 2017 Drift Chamber meeting
  
 
= Connection =
 
= Connection =
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#*[https://halldweb.jlab.org/wiki/index.php/2017_mcsmear_Workplan#CDC_.2F_FDC mcsmear workplan]
 
#*[https://halldweb.jlab.org/wiki/index.php/2017_mcsmear_Workplan#CDC_.2F_FDC mcsmear workplan]
  
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= Minutes =
 
= Minutes =
  
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Participants: Curtis, Mike, Naomi (CMU) Alexander A., Beni, Chris, Simon, Sergey, and Lubomir (JLab).
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Participants:Naomi, Alex B., Dr.Mike Staib (CMU) Alexander A., Beni, Simon, Sergey, and Lubomir (JLab).
  
 
== CDC ==
 
== CDC ==
  
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- We discussed briefly the effect of the space charge on the dE/dx in the CDC (as reported on the analysis meeting). This is a project that requires fitting of the dE/dx angular dependence for different particles (electrons, pions, kaons, protons) and correcting for it, which will significantly improve the PID. Sergey: the effect will depend also on the CDC HV. Curtis proposed to contact Klaus Peters and Nacer (GSI) since they were interested in the dE/dx studies.
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- 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).  
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- Naomi discussed with Beni what should be put in the CCDB for the CDC threshold.
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- Chris: the CDC cables were disconnected and re-routed (by Nick) to have more slack and better access to the electronics. Once cables are re-connected Nick will test them with the f125 pulsers. Naomi will contact Nick about a few channels with lower gain to be tested.
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- 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 
  
 
== FDC ==
 
== FDC ==
  
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- Alex A. pointed again on the pattern seen in the FDC efficiency, reported also yesterday on the analysis meeting. It may come from the inefficiency in the field wire region, but to have this effect the track has to pass through this region in all the chambers (four required) in the same package. Simon and Alex will further investigate this.
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- 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.  
  
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- Fernando submitted a PR for additional LV modules and a chassis to improve the FDC threshold segmentation by a factor of 4 - will have one threshold per chamber. A new distribution box is need, as well, and Nick was working on it.   
 
  
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== Tracking ==
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== fADC125 ==
  
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- Mike is done with the alignment improvements. Curtis: Alex Barnes will be joining the CMU team and will continue with the alignment studies.  
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- Naomi got from Cody the firmware for self-triggering and will test it. Any channel above the threshold generates the trigger.  
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== MCSMEAR work plan ==
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- Names were assigned to the CDC/FDC tasks (as formulated by Sean on the analysis meeting) needed to match MC and data. We discussed at what level the parameters in MC have to be smeared. It was not clear how to do this for some of the tasks, still the list is to be used as a guide.
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== Other ==
 
== Other ==
  
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- TRD: two modifications will be made on the TRD prototype for the fall run. The drift gap will be increased from 2 to 3.2cm and the entrance window will be replaced with a thinner material - chromium foil.
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- 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.
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Revision as of 17:00, 7 September 2017

September 7, 2017 Drift Chamber meeting

Connection

  1. Instructions for Bluejeans meeting connection
  2. Meeting ID: 290664653

Headline text

  1. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.

Agenda

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


Minutes

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

CDC

- 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

FDC

- 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.


fADC125

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

Other

- 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.

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