Patent ID: 8633692
Filing Date: 2014-01-21
Classification: F25B,G01R

Abstract:
1. A nuclear magnetic resonance (NMR) apparatus, the apparatus comprising: a cryostat, said cryostat structured for holding and maintaining liquid helium; a superconducting main field magnet coil system disposed in said cryostat, said magnet coil system generating a homogeneous magnetic field of at least 3T; a gradient coil system, said gradient coil system generating a gradient strength of at least 10 mTm a refrigerator, a pulse tube cooler or a Gifford-McMahon cooler, wherein, in all states of operation of the NMR apparatus without gradient switching, said refrigerator provides a cooling capacity which is at least 0.3 W above an overall power loss (thermal input) of said cryostat; a buffer container disposed outside of said cryostat; an evaporation line connected between said cryostat and said buffer container for transporting helium evaporated from said cryostat to said buffer container; and a return line connected between said buffer container and said cryostat for returning evaporated helium, which has been collected in said buffer container, into said cryostat.