| 摘要 |
PURPOSE:To obtain high uniform magnetic-field distribution by symmetrically arranging first and second coil groups, holding a plane in space, mounting first-fourth saddle-shaped coils to each coil group and forming these coils under specific conditions. CONSTITUTION:First and second coil groups 1, 2 having the same constitution are disposed symmetrically into space organized of X, Y and Z axes, holding XY planes. The coil group 1 has first-fourth saddle-shaped coils 11-14. The saddle-shaped coils 11, 13 and 12, 14 are constructed and disposed symmetrically, holding a Z axis respectively, the length of the arcuate sections of separate saddle-shaped coil is brought to length where angles facing both ends of these arcuate sections from the Z axis are at 90 deg., and angles where straight lines facing the arcuate sections of each saddle-shaped coil from an origin forms with the Z axis are set at one of the angles of aperture to the Z axis from the origin represented by Z/r satisfying respective formula shown by the values of cylindrical coordinates (r, phi, Z). The same applies to the coil group 2. Accord ingly, a magnetic field proportional to (X<2>-Y<2>), an error of which is reduced extremely, is generated selectively, thus acquiring uniform magnetic field distribu tion.
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