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1. Download Magnet_LHe_Fill_Checklist.docx file, fill in all the "initial parameters" and get ready to fill the rest of the fields during the fill.

Precooling (To be Tested on 2024-04-20)

1. Set the Separator flow to 20 slm (or higher) at least 2 hr before the fill. In the operational mode, separator flow should be always 20slm so you can skip this step.
2. If the Liquifier that you are going to use is already in the Idle mode, then please switch it to "Liquefy mode". If the liquid level is having large fluctuations which leads to the liquefier to automatically switching to Idle mode, then you can go to the settings and increase the "Dewar High Level" from 84%(~210L) to 86%(~215L) that way we can keep the Liquefier in the "Liquefy mode" throughout this procedure, and remember to set it back to 84% once the fill is done.
3. Read the inlet flow of the liquefier, F_in.  Remember F_diff = F_in - 45, where 45 SLM is the typical flow rate.
4. Change the set point of the Magnet Bypass Flow PID control to 50 + F_diff SLM.  Do not enable the PID control at this point.
   
5. Open VJVA/B.
6. Wait for 10 seconds, and then close VPC.  Move to the next step immediately.
   
7. Open and close VJVT for 1-2 seconds.  Repeat this until the magnet pressure goes up to 6 psi.
   
8. Enable the Flow PID control of the Magnet Bypass.
9. Open VJVT.
10. Confirm that the liquefier is still in "Liquefy mode".  If not, switch to "Liquefy".
    
    1. At this time, the liquefier will flow exactly the LHe amount that it is producing, to cool the line.
11. Wait for at least 30 mins.  You will see the magnet pressure and Dewar pressure are closer to each other.

Precooling

1. Set the Separator flow to 20 slm at least 2 hr before the fill. In the operational mode, separator flow should be always 20slm so you can skip this step.
2. If the Lquifier that you are going to use is already in the Idle mode, then please switch it to "Liquefy mode". If the liquid level is having large fluctuations which leads to the liquefier to automatically switching to Idle mode, then you can go to the settings and increase the "Dewar High Level" from 84%(~210L) to 86%(~215L) that way we can keep the Liquefier in the "Liquefy mode" throughout this procedure, and remember to set it back to 84% once the fill is done.
3. Then, around 1 hr before the fill, start to cool down the transfer line by opening VJVA/B (ensure VPC is already opened). This is the start time of the transfer.
   1. We skip this step because it should not be necessary, as of 2024-04-19.
4. Wait until TX1  reaches ~100 K. While you are waiting, connect to the CCP and get ready to open the Magnet Return Bypass Valve when TX1 is ~100 K.
   1. We skip this step because it should not be necessary, as of 2024-04-19.
5. Set Magnet Bypass Pressure PID to 6 psi.
6. Close VPC.
   1. We might change when we do this step.
7. Quickly open and close VJVT (only for a few seconds) while VPC is open to get the magnet pressure up to 6 psi and then close VJVT.
   Note: you may have to open/close VJVT a few times to reach the magnet pressure to 6psi; as you don't want to leave the VJVT open for more than 30 seconds at this stage.
8. Once magnet pressure reaches 6 psi, check the inlet flow to the liquefier that you are going to use (~45 slm).
   
   1. Can we finish this check earlier??
9. Set Magnet Bypass Flow PID to 50 slm and switch to Flow PID (this is for balancing with ~45 slm inlet flow to the delivery Dewar).
10. Open VJVT and close VPC. Note: The liquefier that you are going to use is still in "Liquefy mode".
11. At this time, the liquefier will flow exactly the LHe amount that it is producing, to cool the line.
12. Wait for at least 30 mins. You will see the magnet pressure and Dewar pressure are closer to each other.

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