Complementary analyses of hollow cylindrical unioriented permanent magnet (HCM) with high permeability external layer

Abstract

In this article, several studies based on analytical expressions and computational simulations on Hollow Cylindrical Magnets with an external soft ferromagnetic material (HCM magnets) are presented. Electromagnetic configurations, as well as permanent-magnet-based structures, are studied in terms of magnetic field strength and homogeneity. Permanent-magnet-based structures are further analyzed in terms of the anisotropy of the magnetic permeability. It was found that the HCM magnets produce a highly homogeneous magnetic field as long as the magnetic material is isotropic. The dependency of the magnetic field strength and homogeneity in terms of the anisotropy of the magnetic permeability is also explored here. These magnets can potentially be used in medium-resolution NMR spectrometers and high-field NMR spectrometers.

Desenvolvimento de um sensor de RMN (ímã e sonda) para aplicações espectroeletroquímicas

“…The bore of the magnet has a radius equal to r 1 , the thickness of the permanent magnet (PM) is given by r 2 -r 1 and the thickness of the high permeability ferromagnetic material is given by r 3 -r 2 . The permanent magnet cylinder is magnetized in the y direction (black arrows) and the resulting magnetic field is in the same direction (red arrow).Source: Adapted from Lobo et al 2017(40). Copyright 2017 Journal of Magnetic Resonance.…”