Four-Square-Coil Systems for the Magnetic Testing of Spacecraft

In the magnetic simulation of space for the testing of spacecraft, a system of four square coils has structural advantages over the more usual circular coils especially for very large coil systems. Theoretical expressions and computed results are presented for the parameters of the possible four-square-coil systems, particularly for the practical ones having integral turns-ratios. Contours of flux density for the system having unity turns-ratio indicate the degree of circumferential variation present.