Abstract: A gradient coil system for use in a magnetic resonance device comprises a main coil having at least two main sub-coils for generating a gradient coil magnetic field in a target volume, a shielding coil having at least two shielding sub-coils for shielding the main coil, and a power supply system configured to adjust a plurality of electric currents. The main coil and the shielding coil are arranged coaxially along a z-axis, wherein the gradient coil magnetic field is aligned with the z-axis and varies along a gradient direction. The gradient coil system comprises N sub-coil groups, with N?2, with each of the N sub-coil groups comprising a main sub-coil and a shielding sub-coil (3a-3d) connected in series. The power supply system is configured to adjust the electric current of each of the N sub-coil groups individually. The system provides strong gradient coil magnetic fields with improved switching time.

Abstract: In a coil arrangement for nuclear magnetic resonance comprising a main coil (13), a shielding coil (14), and at least one correction coil (41), the function of which consists in forming a magnetic field gradient with eddy current properties which are as good as possible, the main coil (13) and the shielding coil (14) are electrically connected in series with the correction coil (41). The deviations of the residual field from the desired design generated by production tolerances are thereby modified by the correction coil in such a fashion that the long-lasting eddy currents are suppressed. This either reduces the waiting time that must lapse after a gradient pulse before a predetermined field homogeneity is achieved or e.g. the deviations from the desired field are minimized in imaging applications.

Abstract: In a coil arrangement for nuclear magnetic resonance comprising a main coil (13), a shielding coil (14), and at least one correction coil (41), the function of which consists in forming a magnetic field gradient with eddy current properties which are as good as possible, the main coil (13) and the shielding coil (14) are electrically connected in series with the correction coil (41). The deviations of the residual field from the desired design generated by production tolerances are thereby modified by the correction coil in such a fashion that the long-lasting eddy currents are suppressed. This either reduces the waiting time that must lapse after a gradient pulse before a predetermined field homogeneity is achieved or e.g. the deviations from the desired field are minimized in imaging applications.