A general method of design of axial and radial shim coils for NMR and MRI magnets

A novel, efficient method for the design of axial and radial shim coils to suppress undesired harmonic orders in regions of homogeneity is presented. It uses two or three positional degrees of freedom as in the conventional method, but it is not required that these positions be the zeros of any of the source functions. The use of the method is shown for first- through eighth-order axial gradient coils, radial gradient coils, X-gradient coils, and ZX-gradient coils.< >