Print this checklist and have it with you while proceeding with the following steps:
Preparation:
- Check the outside gHe pressure and make sure it is below 90 psi. If it's equal, near, or above, then relieve its pressure down to ~80 psi.
- Check with Target Expert on Shift whether the REGX green hand valve is fixed to some pressure during the previous fill.
- Connect to the Cryo Control Computer (via VNC: see Polarized Target System for SpinQuest at FNAL for the instructions)
Procedure:
- Set the liquefier to "Manual" mode.
- Navigate to the liquefier page on the HMI screen.
- Open SVP(A/B).
- Navigate back to the "Overview Screen".
- Start pre-cool phase: Open VPC → Open VJV(A/B) → Monitor TX1, TX2, TX3
- Charts of TX1, TX2 & TX3: https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/cool_down.php
- TX1 goes down below 100 K in 5 minutes. If not, there should be a problem.
- After ~8mins:
- Open the magnet-bypass valve (i.e. the black hand valve right next to the magnet flow controller),
- Open the Magnet Return flow, by changing the flow mode to "OPEN" on the "THCD_401_Main.vi" on the Cryo Control Panel, and
- Open VJVT on the HMI screen.
- After ~1min: Close VPC and monitor magnet pressure.
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** Note: If the REGX green hand valve is fixed (check with Target Expert on Shift), then do not change it: just proceed with step #10 *****
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> If you need to change the pressure difference between the magnet and the Dewar then use the REGX all the time to maintain the pressure difference that you need (eg: ~4psi) - 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).
- Fill the magnet until the level shows ~44%.
- Keep monitoring the liquid amount and the pressure at https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/transfer.php.
- Stop the fill if the level reached ~44% or any sudden change occurred during the transfer indicating a problem.
- Open VPC
- Close VJVT
- Close VJV(A/B)
- Navigate to the liquefier page on the HMI screen and close SVP(A/B) → Switch the Liquefier to "Liquefy mode".
- Wait for 1-3 minutes until the magnet pressure (on the HMI screen) goes down to 1 psi.
- Close the Magnet bypass hand valve.
- Change the mode of the Magnet Return flow from "OPEN" to "AUTO" on the THCD_401_Main.vi , and then click the "Automation" toggle switch.
- Make sure that you leave the VPC open, to capture all the boil-off from the transfer line until it is warm (check TX1). — We need not check TX1 but let VPC open, correct?
- Calculate the transfer efficiency of the transfer using https://e906-gat1.fnal.gov/data-summary/e1039/ (see the following screenshot as an example), and write an elog entry on UVA elog.
