| 摘要 |
PROBLEM TO BE SOLVED: To obtain a superconducting magnet which can prevent deterioration of uniformity of a magnetic field due to change of an environmental temperature with low running cost, and prevent the dimension of air gap between facing vacuum thermal insulation vessels from being reduced. SOLUTION: A pair of vacuum thermal insulation vessels 103 in which superconduding coil groups 101 are accommodated are arranged face to face. These are covered with a decorative cover 15 which can be divided into an inside plate 15a, an outside plate 15b and a side plate 15c. Ferromagnetic segments 21 are detachably arranged on the inside plate of the decorative cover 16. According to temperature change of seasonal long period, the segments 21 exposed by detaching the side plate 15c are attached or detached, and deterioration of uniformity of a magnetic field which is caused by temperature change is compensated. Compensation of deterioration of uniformity of a magnetic field which is caused by temperature change is enabled at a low cost without consuming energy. Since the segments 21 are arranged in a vacant space, the dimension of an air gap is not reduced. |
