SUPERCONDUCTIVE ELECTROMAGNET

PROBLEM TO BE SOLVED: To protect a motor which can maintain a freezer and drives the freezer from leakage magnetic flux of a superconductive electromagnet without degaussing the superconductive electromagnet. SOLUTION: The superconductive electromagnet is provided with a magnetic shield 21 protecting the motor 11 driving the freezer cooling a cooling medium in a coil container where a superconductive coil is stored with the cooling medium, from leakage magnetic flux of the superconductive coil. The magnetic shield has a pair of ferromagnetic material boards 21a and 21b which are oppositely arranged across the motor. The shield draws in leakage magnetic flux of an opening space sandwiched with a pair of the ferromagnetic material boards into a pair of the ferromagnetic material boards. Thus, magnetic flux density at the periphery of the motor is reduced and the motor is magnetically shielded. The freezer and the motor can easily be maintained by using the opening space which is folded and formed in a pair of the ferromagnetic material boards. COPYRIGHT: (C)2007,JPO&INPIT