1. Fill up the low pressure vessel from the central liquid nitrogen distribution system by turning the level meters (middle unit of the control panel) on and opening V4. At the required level (between 45% and 55%) the fill will terminate automatically.
2. Attach the scroll pump to the permanently mounted turbo pump under the monochromator. with the valve between the turbo pump and the monochromator closed. Turn the turbo on. If at any time during the cool down the vacuum in the mono falls below 10–6PSI, stop the cooling, turn off the ion pumps and open the valve to the turbo pump.
3. If the vacuum stays better than 10–6PSI, start filling the high-pressure side following steps 4 through
4. Set the cryopump frequency to 20 RPM (Use the arrow up and down buttons on the square blue controller above the level meters).
5. Open V6 high-pressure vent, V5 vent and V10 bypass valves.
6. Open V3 high pressure fill valve.
7. Start openning V1 flow valve while keeping V2 return valve closed (blue handles).
8. Wait until temp is –177°— -182° for the 1st crystal and –100 for the 2nd crystal. By that time liquid will be coming out through all vent valves.
9. Open V12 for short time until liquid nitrogen comes out through it as well, then close.
10. Close V6, V5 and V3 and open V2 return valve quickly. If the pressure in the buffer builds up above 30 PSI open V6 briefly to release the extra gas.
11. Turn on the cryopump and close V12 (the bypass valve). Now the fluid is running in closed cycle trough the 1st crystal.
12. If the buffer level goes below 50% top up the high pressure side following the Standard Operating Procedure for Topping Off the Cryostat Buffer (several times if necessary) until the level of the buffer stabilizes at a value between 75% and 100%.
13. Increase the frequency of the cryopump from 20RPM to the desired value.
14. Connect the outlet of the constant pressure module (the black device mounted on the gas outlet of the side dewar ) to the inlet of V6. Make sure the pressure builder of the dewar is set at 60 PSI.
15. Open V6 and make sure the differential pressure in the buffer is equal to the desired value. If not adjust the constant pressure module by turning the black knob very slowly.