A bakeable cryopump having a housing and means to removeably receive the displacer end of a cryogenic refrigerator to cool internal cryopanels said cryopumps adapted for removal of the refrigerator without loss of vacuum inside the cryopump and further adapted to be heated under vacuum to remove pumped gases primarily water so that the cryopumps after cooling can be used at vacuum of at least 10-10 Torr.
