Patent ID: 7245128

Claim:
An apparatus comprising: main coils arranged face to face with each other, so as to form a space therebetween for a magnetic field; a coil container for each of said main coils; and a magnetic field homogeneity adjusting apparatus arranged between said main coils and said magnetic field, to provide homogeneity adjustment of the magnetic field formed in said space; wherein said magnetic field homogeneity adjusting apparatus has a tray comprised of a non-magnetic substance; a face on the magnetic field space side of said tray has at least one opening part for arranging a first magnetic field homogeneity adjusting member comprised of a magnetic substance; a face on the coil container side of said tray has a mount for arranging a second magnetic field homogeneity adjusting member comprised of a magnetic substance larger than said first magnetic field homogeneity adjusting member; and said opening part is located on said magnetic field space side in the vertical direction with respect to said mount.