| 摘要 |
<p>1,221,726. Refrigerating. EUROPEAN ATOMIC ENERGY COMMUNITY. 18 June, 1968 [22 June, 1967], No. 28991/68. Heading F4H. An immersion or vaporization cryostat is cooled by the supply of a coolant, i.e. liquid helium, hydrogen, neon or nitrogen, from a reservoir into the cryostat at the bottom thereof through a suction pipe 10 of internal diameter such that the pressure drop along the pipe is between 1 and 100 Torr. The pipe diameter is preferably between 0.4 and 0.6 mm. The sample to be cooled is sealed within a steel pipe 4 having a copper top and bottom, and the spaces between the pipe 4 and a jacket 7, and between the pipe 10 and a jacket 11, 12 are evacuated. A copper radiation screen 6 and an electrical heating element 9 are provided. Flow of coolant into the pipe 10 may be manually controlled by means of a needle valve 13.</p> |
