Abstract: A vertically compact cryostat includes a housing 2 having a cylindrical lower chamber 3a containing a superconducting coil 1 and a contiguous, larger diameter, overhanging upper chamber 3b serving as a liquid helium reservoir. An annular liquid nitrogen tank 15 surrounds the lower chamber and underlies the upper chamber overhang to thermally insulate the helium and minimize the evaporation thereof. The assembly is completed by a metallic thermal shield 17 attached to the tank and enclosing the housing, and a vacuum vessel surrounding the tank and shield.

Abstract: A cryogenic vessel comprises a liquid helium tank including a substantially flat top wall and which contains therein a cryogen-cooled electrical apparatus. The helium tank is surrounded by a radiation shield provided with a cooling tube through which evaporated helium gas flows and the radiation shield is then surrounded by an outer housing. In order to evenly cool the top wall of the cryogen tank, it is provided with a heat conducting plate, a cooling coil or a plurality of evenly distributed inlets for substantially evenly cooling it.