Magnetic Noise Modeling and Suppression in Laminated Nanocrystalline Magnetic Shielding Barrel Considering Anisotropy

Nanocrystalline alloys provide a low magnetic noise environment for spin-exchange relaxation-free (SERF) magnetic field measurement devices. The effective permeability and conductivity are significantly influenced by the laminated structure and anisotropy of nanocrystalline materials. Consequently, the magnetic noise modeling and suppression in the laminated nanocrystalline magnetic shielding barrel considering anisotropy are investigated in this article. We first construct a magnetic noise model of a nanocrystalline barrel considering anisotropy and analyze the influence of the homogenized thickness on magnetic noise. Second, the remanence of nanocrystalline materials increases magnetic noise. A piecewise demagnetization method is proposed to reduce remanence and suppress the magnetic noise of the nanocrystalline barrel. Finally, the proposed magnetic noise calculation model and piecewise demagnetization method’s effectiveness are experimentally verified. The magnetic noise error between the calculation and experiment is 6.1%. As the homogenized thickness increases, magnetic noise initially decreases and then rises. Compared to the conventional demagnetization method, the novel demagnetization approach reduces the total remanence and magnetic noise by 65.80% and 12.95%, respectively. This research provides theoretical and technical support for the performance improvement of the SERF magnetic field measurement devices.