| 摘要 |
PURPOSE:To obtain magnetic field uniformity without increasing weight and complicating structure and without narrowing magnetic-field forming space by installing a columnar permanent-magnet segment having the axis of magnetization in the radial direction and a yoke magnetically surrounding the segment and allowing the segment to be rotatable in the circumferential direction in the yoke. CONSTITUTION:Each four columnar permanent-magnet segments 5 having the axes of magnetization in the radial direction are mounted rotatably in the circumferential direction and tightly inserted in each four holes 4 in opposed two pieces 2, 3 shaping the magnetic pole sections of an S pole and an N pole. Consequently, the segments 5 are turned in the circumferential direction a proper quantity in the holes 4, thus adjusting each axis of magnetization of the four segments 5, then correcting the magnetic field nonuniformity of a formed magnetic field B. As a result, a subject P on a bedstead is arranged into the magnetostatic field B correcting the nonuniformity of the magnetic field while a transmission unit is driven by pulse sequence by the operation of a sequencer, and specified pulses are applied. Accordingly, weighting is not caused and structure is not complicated, and diagnosic space or magnetic-field forming space, is not narrowed.
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