Generation of uniform magnetic fields with electrically alterable field direction in a geometric plane

Abstract

For the convenience of construction and operation of a well-defined uniform magnetic field source, a structure of two orthogonal sheet current loops (TOSCLs) is proposed. The distributions of the magnetic field uniformity inside the TOSCL are investigated. Self and mutual inductances of the TOSCL structure are studied. Physical factors influencing the current amplitudes are discussed. A main advantage of the TOSCL is its simplicity of construction, especially for dimensions exceeding 0.5 m on a side, when compared with circular coils of the same comparable size. The H-field distribution in the TOSCL is easier to determine than in any other uniform magnetic field generator. Physical factors such as self inductance and frequency do affect the amplitudes and phases of the feeding currents. It is suggested that the sizes of the two orthogonal sheet loops be nearly the same so that the current phases and H-field direction can be easily handled. When both of the two loops are fed by currents, the influence of frequency and self-inductance on the H-field direction can be negligible. However, no matter whether either or both loops are used, this influence on the H-field strength should be noted, especially when the frequency exceeds 300 kHz. >