초록 ▼

Methods and apparatus are provided for minimizing heat introduced by electrical leads into the cryogenic liquid in which a superconducting magnet is immersed. The electrical leads have normal portions extending from exterior of the cryogenic liquid containment vessel and thereinto and superconductin

Methods and apparatus are provided for minimizing heat introduced by electrical leads into the cryogenic liquid in which a superconducting magnet is immersed. The electrical leads have normal portions extending from exterior of the cryogenic liquid containment vessel and thereinto and superconducting portions extending vertically downward therefrom and connected to the magnet. Means are provided to lower and raise the level of cryogenic liquid around the superconducting portions of the leads to fully immerse the supercoducting portions during periods of magnet energization and expose selected segments thereof when the magnet is de-energized. When exposed, the non-immersed segments provide a thermal resistance between the normal metal portions and the cryogenic liquid.

대표청구항 ▼

In combination, a superconducting magnet and cooling apparatus therefor, said cooling apparatus comprising: a containment vessel for cryogenic liquid, said superconducting magnet being disposed within said containment vessel; electrical leads connected at a lower end to said superconducting magnet a

In combination, a superconducting magnet and cooling apparatus therefor, said cooling apparatus comprising: a containment vessel for cryogenic liquid, said superconducting magnet being disposed within said containment vessel; electrical leads connected at a lower end to said superconducting magnet and extending a vertical distance thereabove within said containment vessel and exterior of said containment vessel for connection to an external power source, said electrical leads having superconductive portions; and level adjustment means to alternately lower and raise the level of cryogenic liquid within said vessel around said leads between a lower level, at which selected superconductive segments of said leads within said containment vessel lie above the cryogenic liquid providing thermally insulating barriers between said cryogenic liquid and exteriorly extending lead segements, and an upper level, at which said selected superconductive segments are immersed in cryogenic liquid and are electrically superconducting.