CRYOSTAT HAVING A FIRST AND A SECOND HELIUM TANK, WHICH ARE SEPARATED FROM ONE ANOTHER IN A LIQUID-TIGHT MANNER AT LEAST IN A LOWER PART

摘要

A cryostat for subcooled (2.5 K) liquid helium includes two separate helium tanks. A Joule-Thomson cooling unit includes a heat exchanger in the lower part of the first helium tank and uses liquid stored in the second helium tank in order to cool the subcooled liquid helium stored in the lower part of the first helium tank. The Joule-Thomson cooling unit draws in liquid helium either directly from the second helium tank or from the first helium tank, which is replenished via the gas phase from the second helium tank. In this way, the subcooled liquid helium of the first helium tank can be cooled for a long time from a combined stock of liquid helium in the first helium tank and the second helium tank. The second helium tank may be arranged adjacent or surrounding the first helium tank to maintain a lower overall height of the cryostat.