| 摘要 |
PROBLEM TO BE SOLVED: To provide superconductive magnetic resonance imaging equipment suppressing the necessity of recooling a superconductive coil when reoperating a refrigerator or the like after stopping its operation and quickly reoperating it without enlarging the equipment. SOLUTION: A demagnetization control system 28 determines whether a refrigerator power supply 27 and the refrigerator 26 are operated or not. The control system 28 determines the liquid level inside a low temperature vessel 22 based on an output signal from a liquid level gauge 30 or the temperature of the superconductive coil 2 based on an output signal from a temperature sensor 29. The system 28, when the power supply 27 or the refrigerator 26 stops the driving, determines whether or not the superconductive coil 2 reaches a predetermined upper limit temperature based on the output signal from the sensor 29 or the liquid level gauge 3 and, when reaching the predetermined upper limit temperature, opens a switch 23A by a heater power supply 25 to let a current from the superconductive coil 2 pass to a protective resistance 24. COPYRIGHT: (C)2005,JPO&NCIPI |
