SUPERCONDUCTING MAGNET

PURPOSE:To prevent occurrence of quenching of a permanent current switch by incorporating two sets of the switches in refrigerant for one permanent current switch. CONSTITUTION:Two sets of permanent current switches 20a, 20b for energizing/ deenergizing two adjacent superconducting coils are contained in one refrigerant box 2 for the switch. Thus, when the two sets of the adjacent switches 20a, 20b are contained in the one box 2, the size of the box 2 is increased as compared with the one box when the individual boxes are contained as prior art. Thus, since a natural frequency of the box 2 is increased, it is not deviated from an operating frequency of a moving body placed with a superconducting magnet to prevent resonance, and hence quenching of the switches 20a, 20b can be prevented.