A magnet array is disclosed which is suitable for inter alia producing a
remote field for use in unilateral magnetic resonance. In the "Magnet
Array", two separated magnets, which are magnetized along a substantially
same collinear magnetization direction, produce a field with a local
maximum centered above and between them. The field produced by the two
separated magnets is substantially parallel to the collinear
magnetization direction of the two separated magnets. A third magnet is
centered between the two separated magnets. The third magnet has a
magnetization direction which is substantially parallel to the collinear
magnetization direction of the two separated magnets. The third magnet
produces a field which is substantially parallel to the collinear
magnetization direction of the two separated magnets, and adds to the
increasing field below the local maximum point produced by the two
separated magnets. The field of the third magnet, which decays with
distance, adds to the increasing field below the local maximum point. The
position of the third magnet is selected in order to generate a total
field which has at least one of its first and second spatial derivatives
with respect to the distance above the magnet array substantially equal
to zero.