...

• The magnet already contains LHe, i.e. the magnet LHe level > 0%.
• The fridge valves (i.e. run and bypass valves) are fully closed.
• You can access and control the QT HMI and the Cryo Control Panel (CCP).
• You can access the strip charts on the data-summary page, particularly these preset pages;
  
  • Transfer-Line Cool Down:  https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/cool_down.php
  • LHe Transfer:  https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/transfer.php

Procedure (Since 01/25/2024)

Note: Select the Dewar that you are going to use to fill (Liq should contain at least 200 L of Helium), and then change Dewar Set pressure to 5.7 psi at least 3 hours before the fill.

1. The Liquefier can be on "Auto +Idle" mode (or it may be on "Auto + Liquefy" mode), if not, then change the mode of Liq to Auto + Idle.
2. Download Magnet_LHe_Fill_Checklist.docx file and fill all the "initial parameters" and get ready to fill the rest of the fields during the fill.
3. Start to cool down the transfer line by opening VJVA/B (ensure VPC is already opened). This is the start time of the transfer.
4. Wait exactly for 4 mins. While you are waiting, connect to the CCP and get ready to open the Magnet Return Bypass Valve right after 4 mins.
   Also note that you will have to perform Steps 5, 6, 7 relatively quickly.
   Meanwhile, ensure the mode of the other liquefier is on  "Auto+Idle". If not, set it to "Aut+Idle" mode. **
5. After waiting 4 minutes, disable the auto control of the MagRetBypass valve, using "MagRetBypass_Main.vi" in CCP.
6. Open the MagRetBypass valve fully.
7. Open VJVT and close VPC.
8. Switch the liquefier that you are filling, to "Auto + Liquefy" mode.
9. Monitor the FMR value and if it is increasing above 500slm, then go to the Liquefier Settings and change the "Dewar Set Pressure" to 5 psi.
   You may need to reduce it more (let's say 4.5 psi or even 4 psi) if the FMR keeps increasing. Also, note that you will have to wait at least 30 seconds to see the response. So, please pay full attention and be patience.
10. Monitor the fill paramrters(Magnet level, Delivery Dewar level, Pressures) on https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/transfer.php
11. When the Magnet Liquid level reach 25%, Change the mode of Liq to Manual + Idle.
    Note: This 25% is an estimated value based on the behavior, and it can be changed based on the next fill data. So, coordinate with the Target Expert to explore different values when you fill.
12. Ensure SVNA/B (outlet valve) is closed (it should be automatically closed when you switch the liquefier to the "Manual"+"Idle" mode).
13. Open SV501A/B (inlet valve).
14. Set FC501A/B at 50 SLM.
15. Turn on all the five heaters of Liq.
16. Monitor the pressure differential between Liq & Magnet, PC1 Pressure, and also the FMR.
    If the FMR is increasing above 500 slm, then turn OFF the heaters of Liq. reduce the inlet flow to the Delivery Dewar by changing  FC501A/B value (press enter).
    In Step we set it to 50slm so you can bring it to 45slm or even 40slm if the FMR keeps increasing.
17. Again, monitor the fill paramrters(Magnet level, Delivery Dewar level, Pressures) on https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/transfer.php.
18. Maintain the pressure differential above 3 psi, by adjusting FC501A/B.
19. Monitor everything, until the magnet level reaches 40% (135 L).
20. Close VJVA/B.  Open VPC.  Close VJVT.
    
    1. This is the end time of the transfer.  Record the time, the magnet level and the Liq level.
21. Enable the auto control of the MagRetBypass valve.  Change the set point to 1.5 psi if needed.
22. Change the Liq mode to "Auto+ Liquefy" mode:
    1. The pressure set point is the original value that was set before you started this procedure.
    2. The outlet flow is 40 SLM. Note: you will need to pay attention to this Liquefier for the next ~1 hr / until you change this to 2 slm.
    3. The Liquefier Compressors' coldhead heaters should be automatically OFF, but it's better to confirm on the "Helium Compressors" screen.
       If they are still ON, please turn them off one-by-one (double tap/click on each button for heaters).
    4. If you change the mode of the other liquefier in step6, change it back to Liquefy.
23. Wait until the Liquefier's Dewar pressure gets slightly below 6.5 psi, and then check the actual inlet flow (FC501 A/B I) to the liquefier is above 40 SLM (FC501 A/B Q will be 60 slm).
    This indicates that you can change the Outlet Flow Set point to a lower value like 30slm (follow the next steps over the next ~40 mins).
    Note: Ensure the Dewar pressure doesn't go above 9 psig. If it is rising, you should change the Outlet Flow Set point to 60slm and wait until the Dewar pressure is between 6-7 psi.
24. Repeat step 23 with outlet flow = 20, 10, and 2 SLM.
25. Confirm that the Liq pressure stays around the set point (6.5 slm).
26. Calculate the transfer efficiency using this page  https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/target-LHe-transfer-eff.php

Procedure (until 24 Jan 2024 )

Note: Select the Dewar that you are going to use to fill (Liq should contain at least 200 L of Helium), and then change Dewar Set pressure to 5.7 psi at least 3 hours before the fill.

...