...
- 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.
- 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.
- Read the inlet flow of the liquefier, F_in. Remember F_diff = F_in - 45, where 45 SLM is the typical flow rate.
- 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.
- Enable the Flow PID control of the Magnet Bypass.
- Open VJVA/B.
- Wait for 10 seconds, and then close VPC. Move next immediately.
- Open and close VJVT for 1-2 seconds. Repeat this until the magnet pressure goes up to 6 psi or the Magnet Bypass flow becomes stable around the set point.
- Open VJVT and keep it opened.
- Confirm that the liquefier is still in "Liquefy mode". If not, switch to "Liquefy".
- At this time, the liquefier will flow exactly the LHe amount that it is producing, to cool the line.
- Wait for at least 30 mins. You will see the magnet pressure and Dewar pressure are closer to each other.
...