A Simple Method to Eliminate Shielding Currents Generated when Magnetization is Perpendicular to Superconducting Tapes Wound into Coils

TL;DR

This paper proposes a simple method using an external AC magnetic field to eliminate shielding currents in superconducting tapes, improving magnetic field uniformity for MRI and NMR applications.

Contribution

The paper introduces a novel, practical approach to reduce shielding currents in superconducting tapes, validated through numerical simulations and experiments.

Findings

Effective elimination of shielding currents demonstrated

Field uniformity estimated below 1 ppm

Validated by finite-element simulations and experiments

Abstract

Application of an external AC magnetic field parallel to superconducting tapes helps in eliminating the magnetization caused by the shielding current induced in the flat faces of the tapes. This method helps in realizing a magnet system with high-temperature superconducting tapes for magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) applications. The effectiveness of the proposed method is validated by numerical calculations carried out using the finite-element method and experiments performed using a commercially available superconducting tape. The field uniformity expected for practical applications is estimated to be less than 1 ppm.