A magnetic resonance apparatus has a coil arrangement to generate a magnetic
gradient
field in an imaging volume and an electrically-conductive structure that at least
partially surrounds the coil arrangement and in which, given a temporally changing
current flow in the coil arrangement, eddy currents are caused that produce an
eddy current field interfering with the gradient field within the imaging volume.
For eddy current compensation the coil arrangement has at least two conductor sections
from the group of: a first conductor section that contributes to the generation
of the gradient field, and that additionally generates via the electrically-conductive
structure a first interference factor in the form of a first eddy current field
in the imaging volume, a second conductor section that contributes both to the
generation of the gradient field, thereby generating via the electrically-conductive
structure a second interference factor in the form of a second eddy current field
in the imaging volume, and that generates a field compensating the first eddy current
field, and a third conductor section that contributes exclusively to the compensation
of interference factors in the form of an eddy current field. One of the conductor
sections contributing to the compensation of interference factors is spaced, relative
to the imaging volume, at less than or equal to the distance of one of the conductor
sections contributing to the gradient field.
