Difference between revisions of "Meeting-5-3-2018"

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# NIM publications [https://halldweb.jlab.org/wiki/images/3/3c/GluexCDC_27apr2018.pdf CDC pdf] [https://halldsvn.jlab.org/repos/trunk/publications/GlueXCDC/ svn repository]
 
# NIM publications [https://halldweb.jlab.org/wiki/images/3/3c/GluexCDC_27apr2018.pdf CDC pdf] [https://halldsvn.jlab.org/repos/trunk/publications/GlueXCDC/ svn repository]
 
# Other
 
# Other
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= Minutes =
 
= Minutes =
  
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Participants: Naomi(CMU), Eugene, Simon, Alex B., Sergey, and Lubomir (JLab).
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Participants: Naomi(CMU), Nacer (GSI), Eugene, Simon, Alex A., Alex B., Beni, Cody, and Lubomir (JLab).
  
 
= CDC  =
 
= CDC  =
  
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-Naomi showed plots with several noisy preams with some double-peak structures. Nick looked with a scope at these during the last access, but could not reach the preamp cards being behind the UFO shielding. However, it turned the second noise band disappeared after run 42188, which is when Nick was in the Hall, maybe it was a bad connection of the cable on the fADC.
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- Naomi showed plots demonstrating CDC gradually deteriorates its performance. The efficiency drops at big drift distances significantly; at the same time time-to-distance remains almost unchanged (Alex B.). The most probable explanation is gas contamination. It is strange that the hit efficiency exhibits 30deg phi variation. We discussed also other than gas explanations - some features in the tracking, electronics, etc. The plan is first to fix the gas leakage and than look with cosmics (also before fixing and disconnecting cables).  
  
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- We looked once more at the material scan. Sergey explained the results in more details looking not only at the "photons" but also at the other background signals. Their suppression is not as big as the one for the photons.
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- Nacer finalized his studies of the dE/dx truncation. He simulated pions and protons and looked at
  
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- Changing the hole from 5 to 3.4mm resulted in a reduction of the FDC current (by ~35%), but the CDC current remained similar. Eugene's explanation is that since the current in the CDC comes from both synchrotron and bremsstrahlung, they compensated each other - synchrotron increased by a factor of 3 (beam current increase), while the bremsstrahlung was reduced due to the smaller hole.
 
  
 
= FDC =
 
= FDC =
  
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- Sergey plans to do similar signal analysis for the FDC, as well.
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= Tracking =
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- Sergey showed the effect of the filtering of the "photon" signals on the rho/omega yields as calculated by Simon. Combined with timing cuts, it improves the yields up to 60%.
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Revision as of 17:01, 3 May 2018

May 3, 2018 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 update
efficiency vs n, doca>0.35cm
efficiency vs n, doca>0.15cm
  1. FDC update
  2. NIM publications CDC pdf svn repository
  3. Other

Minutes

Participants: Naomi(CMU), Nacer (GSI), Eugene, Simon, Alex A., Alex B., Beni, Cody, and Lubomir (JLab).

CDC

- Naomi showed plots demonstrating CDC gradually deteriorates its performance. The efficiency drops at big drift distances significantly; at the same time time-to-distance remains almost unchanged (Alex B.). The most probable explanation is gas contamination. It is strange that the hit efficiency exhibits 30deg phi variation. We discussed also other than gas explanations - some features in the tracking, electronics, etc. The plan is first to fix the gas leakage and than look with cosmics (also before fixing and disconnecting cables).

- Nacer finalized his studies of the dE/dx truncation. He simulated pions and protons and looked at


FDC

=

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