| 摘要 |
A method of providing a homogeneous magnetic field in an air gap between two pole shoes by means of coils compensating for pincushion and field gradient distortions. The pincushion distortion is compensated by means of circular conductor paths in which the current flows are individually controlled, the field distortion optionally resulting from current densities of a triangular waveform, where the triangular waveforms are of a wavelength of 1/2<P> of the diameter of the pole shoe and P is an integer from 0 and up to a suitably high value. |
