Difference between revisions of "SBS spot++ (beam size verification)"

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[https://hallaweb.jlab.org/wiki/index.php/Shift_How-To Back to SBS How-To]
 
[https://hallaweb.jlab.org/wiki/index.php/Shift_How-To Back to SBS How-To]
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= Description =
  
 
To image the target or raster size by plotting the hits as a function of raster x and y current, we do the following:
 
To image the target or raster size by plotting the hits as a function of raster x and y current, we do the following:
  
== Taking the Data ==
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= Taking the Data =
  
 
* Take a CODA run under the following conditions.  Make a post to the HALOG with the title "spot++ run XYZ" with XYZ = run number.   
 
* Take a CODA run under the following conditions.  Make a post to the HALOG with the title "spot++ run XYZ" with XYZ = run number.   
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* Stop the CODA run
 
* Stop the CODA run
  
== Analyzing the Data ==  
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= Analyzing the Data =
 
* Log into one of the aonl machines (e.g., a-onl@aonl1).
 
* Log into one of the aonl machines (e.g., a-onl@aonl1).
 
* Run the command: spot_SBS [run-no], where run-no is the CODA run number of the raster scan. If omitted, the most recent run will be analyzed.  
 
* Run the command: spot_SBS [run-no], where run-no is the CODA run number of the raster scan. If omitted, the most recent run will be analyzed.  
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* When prompted, enter y on the command line to post the plots to the HALOG (n does not post to the HALOG).
 
* When prompted, enter y on the command line to post the plots to the HALOG (n does not post to the HALOG).
  
=== Plot Descriptions ===
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== Plot Descriptions ==
 
* '''BPMA y vs x:''' Shows the beam location at BPM A
 
* '''BPMA y vs x:''' Shows the beam location at BPM A
 
* '''BPMA x:''' Shows the number of events at each x value in BPM A
 
* '''BPMA x:''' Shows the number of events at each x value in BPM A

Latest revision as of 16:02, 14 June 2021

Back to SBS How-To

Description

To image the target or raster size by plotting the hits as a function of raster x and y current, we do the following:

Taking the Data

  • Take a CODA run under the following conditions. Make a post to the HALOG with the title "spot++ run XYZ" with XYZ = run number.
    • Beam current: 5--10 uA
    • Raster size: Check run plan
    • Target: Carbon Hole
    • BigBite setting: Check run plan
    • Super BigBite setting: Check run plan
  • Take data until at least 50k events have been reached for sufficient statistics
  • Stop the CODA run

Analyzing the Data

  • Log into one of the aonl machines (e.g., a-onl@aonl1).
  • Run the command: spot_SBS [run-no], where run-no is the CODA run number of the raster scan. If omitted, the most recent run will be analyzed.
  • After a few moments, the plots will pop up
  • When prompted, enter y on the command line to post the plots to the HALOG (n does not post to the HALOG).

Plot Descriptions

  • BPMA y vs x: Shows the beam location at BPM A
  • BPMA x: Shows the number of events at each x value in BPM A
  • BPMA y: Shows the number of events at each y value in BPM A
  • BPMB y vs x, BPMB x, BPMB y: Same as above but for BPM B
  • Beam at target y vs x, …x, …y: Same as above for at the target
  • BPMA Antenna 1, 2, 3, 4: Signal at the four wires of BPM A, one for X+, X-, Y+, Y-, respectively
  • BPMB Antenna 1, 2, 3, 4: Same as above but for BPM B