Jiles–Atherton model prediction and compensation of the hysteresis inside magnetic shields

In a varying low-frequency external magnetic field, such as that experienced by a satellite in low Earth orbit, the effect of hysteresis should be considered for any magnetic-field-sensitive device placed inside a magnetic shield. We divided the residual magnetic field inside the shielding into two parts: an attenuated magnetic field and a magnetization-induced magnetic field. To calculate the residual magnetic field accurately, we introduced the hysteresis Jiles–Atherton model to predict and calculate the magnetization-induced magnetic field. To mimic the varying magnetic field of low Earth orbits, we developed a quasi-Helmholtz coil by controlling the coil current and placed a magnetic-field-sensitive device—a cold atom clock—inside the coil. This clock was operating inside three layers of magnetic shielding. For the Jiles–Atherton model, we adjusted the current of the compensation coil in real time to maintain a stable magnetic field inside the shield. With this compensation strategy, the test result showed that the field variation is reduced from 14.8nT to 1.4nT. Compared with other strategies, this method provides a more accurate and more universal magnetic-field compensation scheme.