Abstract: The invention relates to a low-temperature refrigerator (1) for producing temperatures in a defined low-temperature range, with a cold head (3) which is fitted with a regenerator (6).sup.6) and in which a thermodynamic circulation process (regenerative cold generation process) is carried out to generate cold. To reduce the technical complexity of the cold generation process, it is proposed that the cold head (3) should be a single-stage unit and the physical characteristics of the regenerator (6).sup.7) in the cold machine (1) should be so selected as to ensure that the cold head (3).sup.8) has an optimal cold output in the desired temperature range. (drawing FIG. 2).sup.6) Translator's note: The German text states "7" here whereas "6" would be more in line with the remaining text and the drawing figures. Therefore "6" has been assumed for the translation..sup.7) Translator's note: The German text states "7" here whereas "6" would be more in line with the remaining text and the drawing figures.

Abstract: A refrigerator for cryogenic pumps, cryostats and the like, includes a housing having a cylindrical working volume inside the housing and a displacement element capable of moving in a reciprocal manner within the working volume. The displacement element is driven by a gas drive. To reduce vibrations, the displacement element is forcibly guided.

Abstract: This invention concerns a method of operating a cryogenic cooling device (1) with a cylinder (4, 5) in which a piston (6, 7) reciprocates and with a gas drive (8, 9) which produces the motion of the piston. In order to reduce the vibrations which occur during operation, the invention proposes that the gas drive (8, 9) is controlled in such a way that the piston (6, 7) is only accelerated for part of the stroke.