Difference between revisions of "May 29th"

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== Topics ==
 
== Topics ==
* Optics:
+
*; Optics
: - Check the current optics matrix with Hydrogen data, compare with GMp latest optics.
+
:# Rey checked the current optics matrix with Hydrogen data (plot target variables vs invariant mass etc), compared with GMp latest optics (lower order). It's hard to tell what the GMp version improved. Or suggested to check more carefully (with p_miss).
: - New calibration with Sieve data
+
:# Shujie calibrated the y-theta-phi with Sieve data at 3.57GeV from Marathon run period:
 +
:#:* y_tar at off-center position is slightly improved. Theta-phi seems to have an overall offset;
 +
:#:* the lower order GMp fitting (only 4 terms in theta) can not align the holes very well at the first look. Will check with Longwu how to control the fit.
  
* Beam Energy and Energy Loss
+
*; Beam Energy
 +
: The measured beam energy (HALLA:p) is plotted versus time. In about 100 runs its value 6 MeV lower than the main distribution. Doug suggested that:
 +
:# check the beam energy correction factor (HALLA:dpp) which should not be zero
 +
:# we are currently reading the beam energy at the run start (db_run.dat) which could be wrong if the beam was off at that moment.
 +
*; Energy Loss
 +
: Rey adapted the energy loss class from GMp to Tritium settings, updated target configurations and materials.
  
* Trigger-dependent VDC timing calibration
+
*; Trigger-dependent VDC timing calibration
 
+
: Shujie checked the impact of VDC t0 offset on tracking:
*Replay rawdata with batch farm
+
:#  Nothing obvious with a 5ns offset.
 +
:#  For prescaled runs, can use the adapted triggertime class in analyzer to adjust VDC t0 for different trigger type.
  
 +
*; Replay raw data:
 +
: Rey setup the code to replay raw data with batch farm and store them in tape library. It takes ~ 5 hrs to replay all e'p runs.
  
 
== Slides ==
 
== Slides ==
 +
[https://hallaweb.jlab.org/wiki/images/2/2b/180529_optics_and_others_sbs.pdf optics checks - Rey]
 +
 
[https://hallaweb.jlab.org/wiki/index.php/Image:Optics_Calibration_for_ep_%28Round_1%29.pdf optics calibration-shujie]
 
[https://hallaweb.jlab.org/wiki/index.php/Image:Optics_Calibration_for_ep_%28Round_1%29.pdf optics calibration-shujie]
 +
 
[https://hallaweb.jlab.org/wiki/index.php/Image:Vdc-tracking.ppx.pdf vdc calibration-shujie]
 
[https://hallaweb.jlab.org/wiki/index.php/Image:Vdc-tracking.ppx.pdf vdc calibration-shujie]
  
 
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BlueJeans connection info: https://bluejeans.com/479755873
 
BlueJeans connection info: https://bluejeans.com/479755873

Latest revision as of 17:29, 29 May 2018

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Topics

  • Optics
  1. Rey checked the current optics matrix with Hydrogen data (plot target variables vs invariant mass etc), compared with GMp latest optics (lower order). It's hard to tell what the GMp version improved. Or suggested to check more carefully (with p_miss).
  2. Shujie calibrated the y-theta-phi with Sieve data at 3.57GeV from Marathon run period:
    • y_tar at off-center position is slightly improved. Theta-phi seems to have an overall offset;
    • the lower order GMp fitting (only 4 terms in theta) can not align the holes very well at the first look. Will check with Longwu how to control the fit.
  • Beam Energy
The measured beam energy (HALLA:p) is plotted versus time. In about 100 runs its value 6 MeV lower than the main distribution. Doug suggested that:
  1. check the beam energy correction factor (HALLA:dpp) which should not be zero
  2. we are currently reading the beam energy at the run start (db_run.dat) which could be wrong if the beam was off at that moment.
  • Energy Loss
Rey adapted the energy loss class from GMp to Tritium settings, updated target configurations and materials.
  • Trigger-dependent VDC timing calibration
Shujie checked the impact of VDC t0 offset on tracking:
  1. Nothing obvious with a 5ns offset.
  2. For prescaled runs, can use the adapted triggertime class in analyzer to adjust VDC t0 for different trigger type.
  • Replay raw data
Rey setup the code to replay raw data with batch farm and store them in tape library. It takes ~ 5 hrs to replay all e'p runs.

Slides

optics checks - Rey

optics calibration-shujie

vdc calibration-shujie


BlueJeans connection info: https://bluejeans.com/479755873