Modulation effect peculiar to the magnetic shield with magnetic shaking is presented, in which high frequency external magnetic fields penetrate the shielding wall with converting their frequencies into the low-frequency band of interest for SQUID magnetometry. The process of modulation is analyzed assuming nonlinearity in permeability of the shielding material under the magnetic shaking. The line spectra of the penetrating magnetic fields are well described by the theory. Methods to alleviate this effect are discussed.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering