Magnetic noise analysis and suppression of nanocrystalline spindle-shaped magnetic shielding cylinder

Nanocrystalline magnetic shields provide near-zero magnetic environments essential for the ultra-sensitive operation of spin-exchange relaxation-free (SERF) atomic magnetometers, enabling precise measurements such as magnetocardiography (MCG) and magnetoencephalography (MEG). To enhance sensitivity, this study introduces a magnetic noise (MN) model tailored for a spindle-shaped magnetic shielding cylinder (SMSC), incorporating the effects of structural anisotropy. Additionally, a segmented dynamic demagnetization method is developed, accounting for the anisotropic magnetization characteristics of nanocrystalline materials. The proposed approach effectively improves both magnetic shielding performance and noise suppression.