PolHe3 Punch List For Restart

Step 1

• Restore items noted in HCLOG 3809218 when site access is restored.

Pre-beam Target Work

• Test Kepco in current mode (Bill)
  • New filter (for 180 Hz) to install for current mode operation fix. Can always go to voltage mode if it doesn't work.
  • Establish/verify a known-good production mode

• pNMR issues
  • Software : Software/driver issue needs to be resolved. Checkout during next non-production down time (Moller or SHMS fix)

• EPR problems : [1] saw some progress on Tuesday [2], but issues remain.
  • Tentative plan now is to continue the d2n program by replacing the photo-diode that is placed directly on the pumping chamber (we have many spares).
  • It would be good to write up a procedure to streamline this replacement procedure for us and RadCon

• NMR Calibration Constants : Verify that calibration constants and input values associated with NMR and other polarimetry are consistent and will be correct when the software is restarted
  • [3] [4] [5] [6] [7] (Bill, Junhao, Arun)
    • Add list of calibration runs and what constants apply to what production runs here: PolHe3_Polarization_Measurements

Pending Issues

• Fix the epics variable for target field angle. This is the PV which is calculated from the coils currents that is in the startOfRun entries. It needs a new formula since we changes the coil orientation (Bill)
• Verify that all other EPICS channels are present and are still being archived [Brad]
• Look at trigger related signals on the scope under high load (reftime extra pules, FADC reftime-shaper pileup?, NGC noise/rate questions) [Brad]

• Target Ladder software must throw an error on a 'voltage' readback mismatch! [8] -- Ethan working on this

• Get 3H07B Harp repaired [9] [10]; and a puzzle [11]
  • This is being pursued by Brad, Thia, et al. Still trying to make sure it gets on EES/IC's pre-beam repair list.

• https://logbooks.jlab.org/entry/3807201 Has Arun's note about the unfortunate reference cell alignment vs. the rest of the target ladder.
  • NOTE: "Shift Leader must request a beam that is shifted horizontally to the beam left side by 2 mm to prevent scraping."
  • Is there a way to shift the reference cell position before beam starts?

• USB bridge : Contact with Target readbacks through AnywhereUSB USB bridge still drop out on occasion

• iochc10 issues : Green now: Rebooted 3/2/20 with Dave Gaskell assistance. OPs wished to reboot hung iochc10 [12], noted in December as well [13]
  • Confirm relevant procedures have been updated at MCC (Gaskell, Paul V.?)
  • This runs the Moller cryo controls and should not be rebooted without expert oversight (does not impact operations). D. Gaskell is looking into getting this addressed properly with OPs.

• Compton related items in Hall C beam steer-up procedure still cause confusion between MCC and Shift Crew -- Gaskell?
  • Procedures need to be updated at MCC

• Verify that inputs to 'Scale32'/G0 scalers (ie ROC5) are > 10ns in width. (Brad, Steve)
  • replace the G0 scalers with something newer/better (SIS38xx or similar)

• Online analysis software ready to go? (Sylvester?, Brad)
  • Most should be fine, but are we missing any 'physics' plots?

Pre-beam punchlist

Copied from pre-beam punchlist done just before MC6 shutdown. Some items are completed and just need verification (as needed).

Techs w/ RadCon [Todd (or designate) for cooling jets]

• Turn on turbos for downstream beamline
• Turn on turbos for SHMS and HMS spectrometer vacuums
• Remove the guards on the SHMS and HMS entrance windows (verify)
• Remove the guards on the both upstream and downstream beamline windows (verify)
• Ensure the beamline window cooling jets are in position and on (verify)
• Ensure the target window cooling jets are in position and on (verify)
• ??

Miscellaneous

• [RadCon, RC] RadCon checklist
• [Gaskell] Beamline checklist
• [Brad] Detector/DAQ checklist
• [Walter] Hall checklist
• [OPS, RC] Schedule hot checkout of Hall C arc magnets/power-supplies
• [OPS, RC] Verify all relevant FSDs that may have been masked for the down are known about and ready to unmasked when appropriate
• [Lassiter] Enable all spectrometer magnet supplies, restore production settings for Cryo
• [Gaskell] Moller cooldown
• [Brad] Double check that rotation is enabled in the GUIs for both spectrometers
• [Brad] Ramp all SHMS and HMS magnets to something modest (quick check), or to first kinematic. For example:
  • SHMS: 11.0deg, 7.5 GeV/c
  • HMS: 13.5deg, 4.2 GeV/c
  • NOTE: Coordinate with the target group on the appropriate HB setting so we don't interfere with any target pumping.
• [Techs, Brad?] Do a final check to ensure that there are no potential issues with remote spectrometer rotation
• Restart main alarm handler (resets masked channels)
• Restart target alarm handler (if needed)
• ??