Abstract: Normally granulates of rare earth compounds are used as a heat-storing medium for a low-temperature range below 15 Kelvin. The material costs for rare earths are high. Further, rare earths are magnetic and thus not suitable for all applications. The present heat-storing medium for a very low temperature range is composed of a set (22) of pourable and gastight sealed hollow bodies (30). Each hollow body (30) contains a fill (34) of a low-boiling gas as a storing medium. The hollow body wall (32) is made of metal or ceramic. Thus a relatively inexpensive heat-storing medium is provided whose physical, chemical, magnetic and mechanical properties can be adapted to the respective use by corresponding material selection.

Abstract: A cryogenic pump with an essentially cup-shaped housing (2), with a radiation screen (4) disposed in the housing and also essentially cup-shaped, with an inlet opening (6), with a cold head (3) extending into the housing and the radiation screen, with pump surfaces (15) for condensable gases, disposed on the cold head, with a collecting chamber for liquid condensate developing during regeneration of the pump; in order to make possible a regeneration of the pump in various installation positions it is proposed that the condensate collecting chamber is laterally disposed in such a way that the pump (1) can be regenerated even if attached horizontally.

Abstract: Method and apparatus for checking the operation of a refrigerator-operator cryogenic pump. The method for checking the operation of a refrigerator-operated cryogenic pump having a cold head with at least one refrigerating unit that is equipped with a pump surface. Various data of the cryogenic pump, particularly the net refrigerating power of the refrigerating unit, are interrogated under various operating conditions and these data are compared to rated data. The method and apparatus are also directed to a diagnostic apparatus with which the interrogation is implemented.