Method for reconfiguring a cryostat configuration for recirculation cooling

摘要

A method for converting a cryostat configuration (1) having a first container (2) with a liquid helium bath (3) and a second container (6) which is filled with liquid nitrogen (7) is characterized in that a cooling medium (12) which is in a gaseous state at a temperature of 60K and a pressure of 1 bar, is introduced into the second container and is cooled by a refrigerator (16) by means of a cooling circuit (11), the coolant lines of which are guided into the second container, to an operating temperature of ≦60K. With this retrofit for existing cryostat configurations that utilize both liquid helium and also liquid nitrogen for cooling a superconducting coil, use of liquid nitrogen can be completely avoided and the evaporation rate of the liquid helium can also be considerably reduced without having to re-liquefy the cryogens used.

主权项

1. A method for converting a cryostat configuration having a room temperature vacuum container housing a first container structured for holding a liquid helium bath at an operating temperature which is kept below 5K by means of helium evaporation, wherein the room temperature vacuum container also contains a second container structured to hold liquid nitrogen for thermally shielding the first container and to keep that liquid nitrogen at an operating temperature of between 75 and 80K by means of nitrogen evaporation, the method comprising the steps of:
a) introducing a fluid cooling medium into the second container, the fluid cooling medium being gaseous at a temperature of 60K and a pressure of 1 bar; and b) cooling the cooling medium to an operating temperature of ≦60K using a refrigerator and a cooling circuit, the cooling circuit having coolant lines which are guided into the second container.