Design of Self-Shielded Uniform Magnetic Field Coil based on Improved TFM

Abstract

Aiming at the influence of the magnetic shielding cylinder on the coil performance in the atomic sensor, a transverse self-shield uniform field coil is obtained by using improved target field method (TFM). The coil consists of two coaxial coils that produce the uniform field in the coil center, and the field decays rapidly to zero outside the coil. Based on the improved TFM, the current densities are expanded into triangular series and their Fourier coefficients are obtained from the target field point expected value. Compared with the traditional design method, this method can determine the winding form according to the desired target, and can obtain better uniformity. Through numerical simulation, the designed self-shielded coil has a uniformity of $6.1\times 10^{-4}$ in the target area, and has outstanding self-shielded effect. This paper not only improves the uniformity, but also further solves the coupling problem between the coil and shield. This is beneficial to the performance improvement of the magnetic compensation system in atomic sensors.