A
cryostat configuration (10), with at least one
cryostat (11), which has at least one first chamber (1) with supercooled
liquid helium having a temperature of less than 4 K and at least one further chamber (2), which contains
liquid helium having a temperature of approximately 4.2 K, a
Joule-Thomson valve (3) being disposed in the first chamber, wherein the first chamber is separated from the further chamber by a thermally insulating barrier (4), wherein
helium from the first or the further chamber expands through the
Joule-Thomson valve into a pump-off
pipe (13), which is in
thermal contact with the
helium of the first chamber and supercools the latter, and wherein the pump-off
pipe is directly or indirectly in
thermal contact with the further chamber during its further progression and is then connected to the inlet of a pump (14), is characterized in that the outlet of the pump and / or an outlet for evaporating
helium of at least one of the cryostats is fluidically connected to the further chamber through a cryogen
pipe (15), and that the cryogen pipe has a
branch-off device (16), which returns a
partial current of the helium located in the cryogen pipe into the further chamber. In this way, the helium consumption and therefore the operating costs are reduced while the pressure in the first chamber remains constant.