Finite-element simulations of hysteretic ac losses in a magnetically coated superconducting tubular wire subject to an oscillating transverse magnetic field

TL;DR

This paper uses finite-element simulations to analyze how magnetic shielding affects ac losses in a superconducting tube under oscillating magnetic fields, revealing conditions for significant loss reduction.

Contribution

It introduces a numerical approach to study hysteretic ac losses in superconducting heterostructures with magnetic shielding, highlighting the impact of support placement and permeability.

Findings

Shielding inside slightly increases ac losses.

Shielding outside can reduce ac losses by orders of magnitude.

Loss reduction depends on permeability and magnetic field amplitude.

Abstract

Numerical simulations of hysteretic ac losses in a tubular superconductor/paramagnet heterostructure subject to an oscillating transverse magnetic field are performed within the quasistatic approach, calling upon the COMSOL finite-element software package and exploiting magnetostatic-electrostatic analogues. It is shown that one-sided magnetic shielding of a thin, type-II superconducting tube by a coaxial paramagnetic support results in a slight increase of hysteretic ac losses as compared to those for a vacuum environment, when the support is placed inside; a spectacular shielding effect with a possible reduction of hysteretic ac losses by orders of magnitude, however, ensues, depending on the magnetic permeability and the amplitude of the applied magnetic field, when the support is placed outside.