3-dimensional magnetic field calculation for an arrangement of s.c. coils with an outer magnetic core

To determine the maximum current density for an arrangement of s.c. coils at a given temperature, the magnetic field distribution within the coils has to be known exactly. The magnetic field distribution due to the coils is determined by replacing the coils by current filaments, and use of the Biot-Savart equation. Better results are obtained when the Biot-Savart equation is integrated over finite coil elements of pregiven form, for which analytic integration is possible. The outer iron core is presented by magnetic surface polarities. The paper describes the combined use of above methods for the total field computation, and compares computed and measured results