CALCULATION OF THE STATIC MAGNETIC-FIELD IN NONUNIFORM MEDIA

A method is presented for the calculation of the static magnetic held in a paramagnetic or diamagnetic sample. The magnetic field can be cal culated everywhere for any given three-dimensional distribution of mag netic susceptibility. In particular, the method may be used to evaluat e the field in regions of nonuniform susceptibility. Solutions are cal culated directly in a single step by integration over the magnetizatio n current density, requiring considerably less computation than iterat ive methods. The integral may be evaluated either analytically for cas es of special symmetry or numerically otherwise. Results are presented for a number of different three-dimensional susceptibility distributi ons. The method can be applied to a wide range of magnetostatic proble ms encountered in NMR. (C) 1995 Academic Press, Inc.