Calculation of Magnetic Field Noise from High-Permeability Magnetic Shields and Conducting Objects with Simple Geometry

Abstract

High-permeability magnetic shields generate magnetic field noise that can limit the sensitivity of modern precision measurements. We show that calculations based on the fluctuation-dissipation theorem allow quantitative evaluation of magnetic field noise, either from current or magnetization fluctuations, inside enclosures made of high-permeability materials. Explicit analytical formulas for the noise are derived for a few axially symmetric geometries, which are compared with results of numerical finite element analysis. Comparison is made between noises caused by current and magnetization fluctuations inside a high-permeability shield and also between current-fluctuation-induced noises inside magnetic and non-magnetic conducting shells. A simple model is suggested to predict power-law decay of noise spectra beyond quasi-static regime. Our results can be used to assess noise from existing shields and to guide design of new shields for precision measurements.

10 pages

References in corpus (1)

• A low-noise ferrite magnetic shield

Cited by in corpus (14)

• An ultra-sensitive and wideband magnetometer based on a superconducting quantum interference device
• NASDUCK: New Constraints on Axion-like Dark Matter from Floquet Quantum Detector
• Constraints on axion-like dark matter from a SERF comagnetometer
• Nuclear quadrupole resonance spectroscopy with a femtotesla diamond magnetometer
• Optically Pumped Magnetometer with High Spatial Resolution Magnetic Guide for the Detection of Magnetic Droplets in a Microfluidic Channel
• Johnson-Nyquist Noise Effects in Neutron Electric-Dipole-Moment Experiments
• Low-noise environment for probing fundamental symmetries
• A practical approach to calculating magnetic Johnson noise for precision measurements
• Synchronized resistance to inhomogeneous magnetic field-induced dephasing of an image stored in a cold atomic ensemble
• Wormholes with varying equation of state parameter
• Phase Sensitivity and Phase Noise of Cantilever-Type Magnetoelastic Sensors Based on the $\Delta$E Effect
• Scheme for continuous force detection with a single electron at the level of $10^{-27}\mathrm{N}$
• Quantum kinetic theory of flux-carrying Brownian particles
• Sensitivity of ultralight axion dark matter search with optical quantum sensors