Cryopump and process for regenerating said cryopump

A method of regenerating a cryopump using a plural-stage refrigeration unit, the cryopump comprising an inlet valve, a backing pump having a backing pump valve and being connected with an interior of the cryopump, and cold surfaces for the adsorption of light gases and the condensing of remaining gases when the cryopump is operated, the cold surfaces being heatable for regeneration, comprising the steps of:

• closing the inlet valve prior to the regeneration of the cold surfaces;
• opening the backing pump valve;
• heating the cold surfaces until the light gases are desorbed by an adsorption surface comprising activated carbon;
• closing the backing pump valve so that a temperature of the cold surfaces and a pressure in the cryopump interior rise to a level above a triple point value of the gases so that precipitates are released, the temperature being selected so as to prevent the adsorption of the condensed gases;
• removing the precipitates through a conduit having a regeneration valve until at least one of the temperature and the pressure falls below the triple point, the regeneration valve being open at and above the triple point and being closed when the at least one of the temperature and the pressure is below the triple point;
• and
• opening the backing pump valve and discontinuing the heating step when the regeneration valve is closed.

A method for regenerating a cryopump using a refrigeration unit, the refrigeration unit comprising first and second stages having respective cold surfaces, the cold surfaces of the first stage being at a higher temperature than the cold surfaces of the second stage, the cold surfaces being for the adsorption of light gases and the condensing of remaining gases when the cryopump is operated and being heatable for regeneration, the cryopump comprising a backing pump having a backing pump valve connected with an interior of the cryopump, and an inlet valve, wherein the cold surfaces of the second stage are regenerated by the steps of:

• closing the inlet valve prior to the regeneration of the cold surfaces of the second stage;
• opening the backing pump valve;
• heating the cold surfaces of the second stage until the light gases are desorbed by an adsorption surface comprising activated carbon;
• closing the backing pump valve so that the temperature of the cold surfaces and a pressure in the cryopump interior rise to a level above a triple point value of the gases so that precipitates are released, the temperature being selected so as to prevent the adsorption of the condensed gases;
• removing the precipitates through a conduit having a regeneration valve until at least one of the temperature and the pressure falls below the triple point, the regeneration valve being open at and above the triple point value and being closed when the at least one of the temperature and the pressure is below the triple point;
• and
• opening the backing pump valve and discontinuing the heating step when the regeneration valve is closed.

A regeneratable cryopump, comprising:

• a housing having an interior space, said housing including an inlet valve and heatable cold surfaces,
• a backing pump connected to said interior space;
• a refrigeration unit for cooling said cold surfaces;
• a discharge conduit including a regeneration valve for the removal of precipitates from said interior space;
• and
• a temperature sensor connected to said regeneration valve for sensing the temperature thereof and for generating a signal representing the temperature for actuating said regeneration valve.