The first cooling down requires to have the superinsulation (or Outer Vacuum Chamber -OVC-) well pumped. Then the magnet/helium tank are pre-cooled to liquid nitrogen temperature at the same time together with the (outer) nitrogen tank. After 1 night the nitrogen can be expelled from the helium tank and the latter can be refilled with liquid helium. Here under the procedure is described in details:

1. The cryostat is warm
2. Connect the dedicated Varian turbo trolley to the OVC pumping port (pumping port valve is closed).
3. Start the rotary pump only. After few minutes open the OVC valve. It might take from few hours to half day before the turbo can be started. The best is to wait 2 hrs, then try to see whether the turbo can be started - i.e. if the turbo reaches full speed (75Krpm) after few minutes.