| 摘要 |
PROBLEM TO BE SOLVED: To enhance stability of a temperature in a cryogenic probe coil, in ultra-high sensitivity NMR equipment. SOLUTION: A low-temperature probe of the ultra-high sensitivity NMR equipment is constituted to be brought into a very low temperature by a cooler. A refrigerant of an ambient temperature (300°K) delivered from a compressor 1 is cooled to 70°K by a counter-flow heat exchanger 2, is cooled thereafter to 30°K by a series of the first stages 5, 6 connected in series to two GM refrigerators 3, 4, and is cooled further to 4°K or less by a series of the second stages 7, 8. The refrigerant comes further into the low-temperature probe through a transfer tube 9 to cool the probe coil 11 to 5-10°K by a heat exchange part 10, cools further a radiation shield 13 to 40-60°K, and takes a round through the counter-flow heat exchanger 2. The high temperature stability is imparted to the reception probe coil of the low-temperature probe by the cooler having high temperature stability. COPYRIGHT: (C)2006,JPO&NCIPI |
