MAGNETIC FIELD GENERATING DEVICE

摘要

PURPOSE:To expand a magnetic field more in a large gap uniformly and stably with high precision by arranging an annular magnetic body in a static magnetic field production area in contact with or closely to a permanent magnet or magnetic pole piece. CONSTITUTION:A magnetic field generating device for a nuclear magnetic resonance tomography device generates a static magnetic field in the gap 2 with a permanent magnet 1 (or magnetic pole piece 7 connected to a permanent magnet 8) forming the gap 2; and the annular magnetic body 3 is arranged on the static magnetic field production area in contact with or closely to a permanent magnet 1 (or magnetic pole piece 7). The permanent magnets 1 and 8 use, for example, Fe-B-R system (R: at least one kind among rare earth elements containing Y) permanent magnets. Consequently, magnetic flux produced by the permanent magnet 1 (or 8) forms a magnetic field through the annular magnetic body 3, wherein a static magnetic field having extremely high uniformity is produced.