Magnet apparatus and mri apparatus

摘要

A magnet device includes two sets of static magnetic field generation sources spaced from each other in the vertical direction such that the uniform magnetic field region (patient space) is between then. Each set has concentric current carrying coils to generate a uniform magnetic field in a first direction (the vertical direction). Several such coils are used in each set, disposed such that when a first axis which is parallel to the first (vertical) direction and passes substantially through the centers of the current carrying coils crosses, at a first point, a second axis which is orthogonal to the first axis and is at substantially equal distance from the respective static magnetic field generation sources, the current carrying coils are disposed in such a manner that when geometrical centers of cross sections of the current carrying coils are projected on a first straight line that is in a first plane containing the first axis, the second axis and the first point and passing through the first point, the directions of the currents of the carrying coils at the respective corresponding projections align alternatively in positive and negative directions on the first straight line.