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changes.mady.by.user M. A. Ishara Fernando

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changes.mady.by.user Kenichi Nakano

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  1. Check the outside gHe pressure and make sure it is below 90 psi. If it's equal, near or above, then relief it's pressure down to ~80 psi.
  2. Insert the stinger into Dewar C.
  3. Set up the power supply for the "pressure builder" of the Dewar C.
  4. Navigate to the "Overview Screen" on QT HMI.
  5. Start pre-cool phase:  Open VPC → Open VJV(A/B) VJVC → Monitor TX1, TX2, TX3
    1. Charts of TX1, TX2 & TX3:  https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/cool_down.php
  6. After ~8mins: Open the magnet-bypass valve (hand-valve right next to the magnet flow controller) → Fully open the magnet return on the Cryo Control Panel → Open VJVT on the HMI screen.
  7. After ~1min: Close VPC and monitor .  Monitor the magnet pressure and maintain ~5psi using the pressure builder on the Dewar C.
  8. Try to regulate the pressure difference of ~4psi between the magnet and the Dewar (during the entire fill), using the pressure builder on the Dewar C.
  9. After a couple of minutes, you will observe that the magnet pressure drops down suddenly and stay around ~1.4-1.5 psi (this indicates that LHe is flowing to the magnet after the pre-cooling of the last part of the transfer line).
  10. Regulate the pressure difference of 3-4 psi between the magnet and the Dewar (during the entire fill), using the pressure builder on the Dewar C.
    1. Charts of LHe Liter & Pressure:  https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/transfer.php
  11. Fill the magnet until the level shows ~44% → Open VPC → Close VJVT → Close VJV(A/B) VJVC → Close Magnet bypass hand valve. Make sure that you leave the VPC open to capture all the boil-off from the transfer line until it is warm (check TX1).
  12. Set the magnet return at about 30 SLM.  Possibly enable the automated control to maintain the magnet pressure at 1.0 psi (which corresponds to about 0.3 psi on Cryo Control Panel).