Finite Element Models for Magnetic Shields Made of Stacked Superconducting Tape Annuli

TL;DR

This paper compares layered and homogenized finite element models for superconducting tape annuli used as magnetic shields, evaluating their accuracy and efficiency in axial and transverse configurations.

Contribution

It introduces and compares two modeling approaches for superconducting tape shields, highlighting their respective advantages and limitations in different geometries.

Findings

Both models perform similarly in axial configurations.

Homogenized model is less practical for transverse configurations.

Layered model offers better accuracy in complex geometries.

Abstract

Stacks of high-temperature superconducting tape annuli can be used as magnetic shields operating efficiently for both axial and transverse fields. However, due to their layered geometry and hybrid electrical and magnetic properties, implementing models of such structures is not straightforward. In this work, we propose two different modelling approaches with the finite element method: layered and homogenized. We compare their accuracy and numerical efficiency for three different formulations (h-phi, h-phi-b, and a-j), in both axial (2D-axisymmetric) and transverse (3D) configurations. We show that both approaches lead to comparable performance in the axial case, but that the homogenized model is considerably harder to use in the transverse case.