Modeling and suppression of magnetic noise in nanocrystalline magnetic shielding system considering residual loss magnetic noise and interlayer effects

Multilayer magnetic shielding provides an environment with low remanence and low magnetic noise (MN) for spin-exchange relaxation-free (SERF) magnetic field measurement devices. Accurately calculating and suppressing MN is crucial for enhancing the sensitivity of the SERF devices. However, existing MN calculation methods often overlook the MN induced by residual loss in multilayer nanocrystalline magnetic shielding systems (MSS) and the effects of interlayer effects in multilayer magnetic shielding. This paper proposes a novel MN calculation model for multilayer nanocrystalline MSS that considers residual loss MN and interlayer effects. Furthermore, to suppress the MN of nanocrystalline MSS, the magnetic properties of the nanocrystalline materials are measured and the nanocrystalline with the best properties is selected. Finally, experimental validation of the proposed MN calculation model for the multilayer nanocrystalline MSS demonstrates that the errors between the experimental and analytical values of radial and axial MN are only 6.43 % and 4.36 %, respectively. This research provides theoretical and technical support to enhance the performance of SERF devices.