METHOD OF DESIGNING DIMENSION OF SUPERCONDUCTING SHIM DEVICE FOR SUPERCONDUCTING MAGNET DEVICE AND SUPERCONDUCTING MAGNET DEVICE

摘要

PROBLEM TO BE SOLVED: To properly design the dimension of a shim device so that the contribution z of the device to a magnetic field in a working volume may become zero (z=0) regardless of the electric current flowing through a shim coil.;SOLUTION: A superconductive magnet device is provided with a magnet coil system containing at least one superconducting magnet coil through which an electric current flows, a shim device including at least one superconducting shim coil, and one or more additional superconducting closed electric current circuits added as options and generates a magnetic field in the Z-axis direction. The magnetic fields which are generated in the z-axis direction by the additional electric current circuits due to electric currents induced at operating do not exceed the magnetic flux density of 0.1 tesla and the shim device generates such a magnetic field that changes at a rate of zk (k: an even number 0f 0) along the z-axis. The shim device is designed so that a variable gseff may substantially become zero and another variable gseff.ct may become 0, particularly, 0.2 millitesla/A.;COPYRIGHT: (C)2002,JPO