Abstract: An elongated fast cycle cryopump device connected to a refrigerant source has a rigid head section adapted to extend through a pass-through opening of a vacuum chamber. The head end section has a feed tube and a return flow passage, the feed tube being connected to a valve for selectively receiving either a relatively cold refrigerant or a relatively hot refrigerant during different phases of operation. A flexible probe section connected to the rigid head end section is capable of being shaped in different ways to assume a preselected or variable configuration within the vacuum chamber workspace and includes a flexible feed tube connected to the feed tube of the head end section for carrying the refrigerants passing through the head section outwardly to the end of the flexible probe section. A flexible outer tubular member surrounding the flexible feed tube provides a return passage for the refrigerants along the flexible probe section and through the head section.

Abstract: The disclosure relates to a closed refrigeration system wherein refrigerant travelling between heat exchangers in the system is diverted to the evaporator in response to operation of a controller which responds to the temperature at the evaporator. Preferably the diverted refrigerant is the liquid phase thereof, separation of the liquid from the gaseous phase taking place between heat exchangers in a preferred embodiment of the invention. When the temperature at the evaporator is at a predetermined value, the controller can shut off the refrigerant diverting portion of the system to provide standard system operation.

Abstract: The disclosure relates to a refrigeration system wherein the evaporator of the refrigeration system is placed within a vacuum system as a "Meissner" coil previously described. Optionally it may be provided with extended surface(s). The cryosurface has a single tube passage for flow of either an evaporating low temperature refrigerant fluid for cooldown and continuous cold operation, or superheated compressed refrigerant gas for adding heat during the defrost cycle. Appropriate valves select whether cold fluid or superheated refrigerant gas flows through the tube in the cryosurface. A recuperative heat exchanger and a superheating exchanger preheat, in two stages, a cold compressed refrigerant gas stream after the gas has been rectified within the system. This superheated gas stream defrosts the cryosurface, flows back through the recuperative heat exchanger where it is recooled and then is reintroduced into the cold cascade heat exchangers.