Impact of aperture angle on magnetostatic shielding performances of magnetic shield cylinders

The spin exchange relaxation free (SERF) atomic magnetometer plays an important role in ultrahigh sensitive magnetic measurements. With the improvement of signal response and the reduction of sensor noise, the sensitivity of the SERF atomic magnetometer is limited mainly by environmental magnetic noise. In order to improve the performance of magnetic shielding, the models of a magnetic shielding cylinder with triangular holes were established in this paper, and the effect of aperture angle (θ) on the efficiency of shielding by a permalloy cylinder was investigated by the finite element analysis. The results showed that the shielding effectiveness decreases first and then increases with the augment of θ. The cylinder showed that the worst shielding effect at θ equals 60°, resulting from the magnetoresistance of leakage flux in the air dielectric. This research focuses on providing theoretical support for the design of magnetic shields and improvement of the magnetic shielding ability.