Left Arm Checks

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

PREX Main<< Information for Shift Takers<<Shift Checklist

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• Look at Hall A General Tools
• Left Arm momentum (GeV)
• Left Arm Q1, Q2, D, Q3 regulators on (yes/no, ask experts)? Check the whiteboard for intended settings
• Left Arm cryo flow level OK (Green)? Yes/No He>60% (Ignore Nitrogen)
• Left Arm NMR OK? Yes/No
  • The NMR field readback is indicated in the "D-N" row of the GUI, the NMR meter is useful only at > ~GeV set points, so if the magnets are too low then the NMR readback will be useless and fluctuating wildly (in which case the Gauss meter readback is useful, indicated in the "D-G" row)
  • The NMR read-back quality can also be determined by looking at the Oscilloscopes in CH main room rack CH01A02 (above the adaq2 terminal). If the NMR is locked then the triangle wave and NMR readback will be synced and locked onto eachother in both scopes.
• Left Arm Q1 B-Field (+/-T), Momentum (GeV/c), Polarity (N/P), current (A)
• Left Arm Q2 B-Field (+/-T), Momentum (GeV/c), Polarity (N/P), current (A)
• Left Arm D B-Field (+/-T), Momentum (GeV/c), Polarity (N/P), current (A)
• Left Arm Q3 B-Field (+/-T), Momentum (GeV/c), Polarity (N/P), current (A)
• Are the magnets properly meeting their setpoints (are the read-back values within 0.5% of the setpoints?) (Also, all magnets should be in negative polarity for Prex/Crex)
  • Check the setpoints and readbacks by clicking on the I(A) menu button and looking at each magnet's GUI independently. Be careful, as you are able to change the settings from within these GUIs.
• Is Left VDC gas flow (top/bottom, indicated by Orange "Gas Flow" panel in Hall A General Tools screen T_VDC/B_VDC l/h readbacks) on?
• Left VDC HV on (top/bottom)? - See VDC HV GUI for more information
• VDC thresholds (All 4 values should be 3.0 V, yes/no) ? See Hall A General Tools bottom right corner
• Left s0/s2m HV on (s0 may be off for production, check with expert)?
• Main Detector HV on/off? - See LHRS MainDet HVs
• SAM HVs on/off? - See SAMs HVs
• Have you checked the quality of the most recent online plots for the Left ARM counting mode DAQ (if a run was taken during your shift)?

Next in checklist >> Right Arm Checks