Beam Modulation

In the process of editing and updating this page. Please contact Juliette Mammei crowder@jlab.org with questions or suggestions.

PREX Main << Expert Tools

How to Run Beam Modulation

• First, make sure Coda is running

• You need to be logged in apar account on adqa3:

  •  ssh apar@adaq3 

• Go to directory:

  •  cd /adaqfs/home/apar/vowen/BMWClient/PyGreenMonster/ 

• Run beam modulation code:

  •  python3 ProductionModulation_Pause10Min.py 

• 1. Beam modulation will automatically run for 7 days
  2. In order to quit beam modulation

     •  control+c 

       to crash out of the beam modulation program.

     •  python3 gm_bmw_clearall.py 

       to clean up the DAQ records and release the EPICS FFB pause states.

Modulation online plots

Task for the analysis shift expert:

For each run, 

• Check the online plot ( the top plot on the BMW plot page), we should see all 7 coils (colorful bars) at least for one super cycle (one bunch). If not, check the beam trips, if this run has a lot of beam trips, then check the other more stable runs. If you still miss one or more coils, then please call Ye: 803-553-3570.
• Check the online plot ( on the BMW Cycle page ).

• BMOD meetings
• Beam Modulation Documentation Portal

Dithering slopes extraction

• To get dithering slope root file for each slug

1. Login to the apar account on aonl2: ssh apar@aonl2
2. cd ~/PREX/prompt/beam-mod/scripts
3. If you haven't done a "gojapan" yet then source setup_japan.tcsh

• To analyze a slug, choose the corresponding list in ~/PREX/prompt/collector/run_list/

1. Next, run ./dit_runlist_alldet.sh ~/PREX/prompt/collector/run_list/slugnumber.list
2. The output root files are saved in the directory: ~/PREX/prompt/beam-mod/rootfiles_alldet_pass1
3. If you want to look at the dithering slopes versus super cycle plot for each slug
   • cd ~/PREX/prompt/beam-mod/rootfiles_alldet_pass1
   • root -l 'dithering_plot_cyc.C(slugNo)'

• To check the singularity for dithering 5 by 5 inverse matrix

1. cd ~/PREX/prompt/beam-mod/scripts/dit_11X12X_txt
2. ./add_runlist_txt.sh ~/PREX/prompt/collector/run_list/slugnumber.list (generate Quartz/AT/BPMs_sensitivity_slugnumber.txt)
3. cd ~/PREX/prompt/beam-mod/scripts/dit_11X12X_txt
4. root -l 'sensitivity_plot_BPMs_uptodate.C(slugNo)' (plots for a whole slug)
5. root -l 'sensitivity_plot_BPMs_uptodate.C(runNo)' (plots for a run to check the singularity after the beam tuning)
   • Check the top two plots of the last three canvas (c43, c44, c45), if the absolute Y mean is smaller than 0.1. We need to retune the beam to get proper dithering slopes.

• To do the dithering correction

1. The pass2 root files should be used.
2. Get the root files cd ~/PREX/prompt/beam-mod/rootfiles_alldet_pass2(mark the out layer points as flag=0)