| 摘要 |
PROBLEM TO BE SOLVED: To prevent solidification of low temperature liquefied gas without using an electric heater in a device cooling low temperature liquefied gas such as liquid nitrogen to a supercooling temperature under the atmospheric pressure by a GM refrigerating machine, and cooling a superconductive member by the supercooled liquid nitrogen. SOLUTION: An inverter is interposed in a power source line of a motor for compression of a compressor of the refrigerating machine, a temperature of a cooling head of the refrigerating machine is detected by a sensor, the inverter is controlled on the basis of the detected temperature to control a flow rate/pressure of the compressor, and feedback control is carried out such that the temperature of the cooling head does not reach a solidification temperature of the low temperature liquefied gas. COPYRIGHT: (C)2005,JPO&NCIPI |
