NMR用超電導マグネットの超流動冷却クライオスタット

抄録

In the past few years, most DNA constructions have been desided through the project of GENOMICS or civilian companies. But these constructions were only “Drawings for protains.” To develop medical science or to new medicines, the actual construction of all protains must be cleared. High-magnetic field NMR, Nuclear Magnetic Resonance, is the most effective way to analize these protains. Along with the “TROSY” method, a magnetic field required to achieve 25.85T (1.1GHz) to clear all protain constructions. Depending on these requiments, recent development of the magnet forword to achieve heiher magnetic field. On the other hand, critical current: I_c of superconductiving wire almost aproechies its critical value, which depends on material property. The only way to have a heigh magnetic field is to decrease its operating temperature. This paper shows the recent development of cooling techniques below 4.2K, using superfluid helium, including the subcooled helium method, on NMR cryostat.