The invention concerns a method for charging an actively shielded magnet
coil arrangement (20) comprising a first partial region (21) which can be
superconductingly short-circuited using an additional switch (23), and a
second partial region (22), wherein the two partial regions (21, 22)
generate dipole moments of different signs. The magnetic fringe field
B.sup.* is measured close to the desired operating state of the
arrangement (20) and operating currents are determined for each of the
two partial regions (21, 22) at which the overall magnetic field B is
free from an additional dipole moment caused by production tolerances to
permit setting of the theoretically optimum fringe field, irrespective of
production tolerances. These operating currents are adjusted taking into
consideration the inductive coupling between the partial regions (21, 22)
through initially charging the entire magnet coil arrangement (20) and,
after closing the additional switch (23), through continuation of the
charging process in the second partial region (22) only. This eliminates
deviations, which are caused by production tolerances, from the optimum
theoretical fringe field of the arrangement (20) in a simple and
inexpensive manner.
