Abstract: The invention relates to a process for regenerating a cryopump (1) that is equipped with an inlet valve (33), with cold surfaces (6, 8, 11) which have a temperature during operation of the pump that effects the condensation and/or adsorption of gases and which are heated for the purpose of regenerating them, the cryopump further including a backing pump (45) that is connected with the pump interior (9) by way of a valve (44). In this process, heating of the cold surfaces begins if the inlet valve (33) is closed and the connection between the pump interior (9) and the connected backing pump (45) is blocked so that, in addition to the temperature of the cold surfaces, the pressure in the pump interior also rises to values that lie above the corresponding values of the triple point of the gas to be removed.

Abstract: The invention relates to a method of adapting a twostage refrigerator cryopump to a specific gas; the cryopump includes a first cooling stage to which pump surfaces are fastened and which is equipped with a heating device; the cryopump further includes a second cooling stage to which pump surfaces are fastened and which, during operation, takes on a temperature of up to 20 K. In order to enable the pump to perform at an optimum level for gases having different vapor pressures, it is proposed to control the heating device in such a manner that the coldest location of the first cooling head or, more precisely, of its pump surfaces, has a temperature which is higher by 5 to 10 K than the vapor pressure temperature of the respective gas associated with the maximum process pressure.

Abstract: The invention relates to a cryopump having a casing (1), a gas inlet opening (8) to which a chamber (30) can be attached through a valve (31), a vacuum pump (18) connected through a valve (16) to the casing, a two-stage refrigerator (4) in the casing as cold source, and pumping surfaces (7, 9, 12, 13) which, on both of the refrigeration stages (5, 11) of the refrigerator, are equipped with an electrical heating means (23, 24). To achieve a great shortening of the time required for regeneration and start-up it is proposed that a sensor (41) be provided to monitor the pressure within the pump casing, and that a control unit (28) be present by which the operation of the cryopump can be monitored and controlled on the basis of the signals supplied by the sensor.

Abstract: A cryopump has a two-stage refrigerator in a housing with a pumping surface area in thermal communication with each stage of the refrigerator for gas-pumping by adsorption or absorption when the refrigerator is operated. A roughing vacuum pump provides a pressure of from about 1 to about 10.sup.-3 mbar to the housing and at least the pumping surface area of the second refrigerator stage is heated sufficiently to prevent gas adsorption or absorption thereon before the cryopump is operatively connected to a space to be evacuated therewith as a starting method for improving the cryopumping of, particularly, helium and a regenerating method after use of the cryopump.

Abstract: A refrigerator has a cold producer with a pneumatically-operated displacer for displacing a working, cold-producing gas. The pneumatic and working gas-supply control is separate from the cold producer and connected thereto by tubes having volumes less than the maximum volumes of the portions of the chamber supplied thereby.

Abstract: A refrigerator cryostat for producing high vacuums at controlled temperatures in a sample chamber has first and second refrigerator stages for progressively lowering the refrigerator temperature to the sample chamber. An independent heater heats the sample chamber to provide, in combination with the refrigerator temperature, the controlled temperatures to the sample chamber. A vacuum pump preliminarily evacuates a casing about the refrigerator stages which is also in vacuum communication with the sample chamber, but a pumping surface in thermal communication with the first refrigerator stage and in the casing cryogenically augments the preliminary evacuation to the high vacuum levels necessary for operation of the refrigerator cryostat at sample chamber temperatures of, for example, from about 10.degree. K. to about 350.degree. K.

Abstract: A cryopump having a generally axially symmetrical housing provided at one end with an entrance opening defined by a plane for passage of molecules of the gas to be pumped and plates defining condensation surfaces arranged to be brought to low temperature for condensation of molecules of the gas to be pumped, and a thermal radiation shield disposed in the region of the entrance opening, with the condensation surfaces being oriented substantially at right angles to the plane of the entrance opening and the radiation shield being composed of a plurality of elongate metal strips so positioned that their longitudinal axes are parallel to the condensation surfaces.