| 摘要 |
<p>Improved cryogenic magnet systems for use in NMR imaging devices comprising an electro-magnet immersed in a first tank containing a first liquid gas, the first tank located in a container evacuated to a high vacuum, a refrigerating system external to said container, and coupling means for coupling a cold head of the refrigerating system to radiation shielding means surrounding said first tank for lowering the temperature of the shielding means to thereby reduce boil-off of said liquid gas.</p> |
