Analysis of cooling and cryostating processes for large superconducting facilities

The processes of preliminary cooling, liquid helium accumulating and specified regime maintaining have been analysed for a system consisting of the helium refrigerator and the super conducting solenoid with cooled current leads. The factors have been revealed which determine the velocity of the processes at each stage and characteristics of the system have been constructed. The conclusions are drawn: 1) The refrigerator scheme should have special outlines which allow to conduct a cooling process with maximum velocity. 2) The cooling rate, as a rule, is limited either by admissible temperature gradient in an object, or by resistance of the line on which gas from the object returns to the refrigerator. Heat emission conditions are of a secondary importance. 3) In cryostating of superconducting facilities with cooled current leads there exists an optimum flux of current leads cooling gas which ensures maximum velocity of liquid helium accumulation or cold production