| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic field generating coil device which is easily handled, entails a low refrigerant cost, and is highly safe. SOLUTION: A coil 2 which generate a magnetic field when a current is applied is housed in a cryostat 3 for the formation of a magnetic field generating coil unit. The coil 2 is composed of a bobbin 21 and a coil winding 22, and the cryostat 3 is equipped with an opening 30 and a refrigerant inlet 31. Provided that the inner volume of the cryostat is represented by V1, and the volume of the coil 2 is represented by V2, the volume ratio V1/V2 ranges from 1.5 to 10. Provided that the area of the refrigerant inlet, the maximum thickness of the cryostat 3 in a center axial direction, and the maximum length of the cryostat 3 in a radial direction vertical to the center axis are represented by S [mm2], L1 [mm2], and L2 [mm2], respectively; S, L1, and L2 are so set as to satisfy a formula, 10<=S<=(L1×L2). |
