A matrix solution for the simulation of magnetic fields with ideal current loops

A matrix formulation is presented for describing axisymmetric magnetic field data with ideal current loops. A computer program written in APL is used to invert the matrix and hence to solve for the coil strengths which are used to represent the field data. Examples are given of the coil representation for 1) measured magnetic data, 2) refocusing fields, and 3) PPM focusing fields.