| 摘要 |
PURPOSE: To achieve homogenization of a main field coil without hindrances of access to a subject's volume from the axis- or cross section-direction by so adopting the number of windings of all partial coils of an adjusting coil that the respective inductance between a main field coil and an adjusting coil is to be eliminated. CONSTITUTION: A magnetostatic field compensatory device is installed with a ferromagnetic homogenizing element 20 at the both sides of a crossing- direction-access opening and at a prescribed position on a face of room-warming opening to compensate at least one component of field noise of a striped spheriform function having the formula of Anm, where n = 1 to 3, for example, n = between 1 or 6, m = 1 to n. A compensatory coil is installed coaxially with a field coil whose partial coils C2i, C1a to C4i and C4a are applied with electricity in reverse direction when the same is activated. All the partial coils C1i, C1a to C4i and C4a are cylinder coils having shorter diameters than those of bores of outer field coils 1a and 1b and coaxial with a common shaft Z. |
