Superconductor Dynamics

TL;DR

This paper analyzes the magnetic flux dynamics in superconductors, focusing on how their ability to resist flux motion affects current carrying capacity, energy dissipation, and the influence of geometry and filamentation.

Contribution

It provides basic formulas for qualitative analysis of flux dynamics in superconductors with various geometries and filament configurations.

Findings

Magnetic flux interaction affects superconductor current limits.

Orientation impacts flux penetration in flat cables.

Filamentation reduces magnetization currents but introduces coupling currents.

Abstract

Superconductors used in magnet technology could carry extreme currents because of their ability to keep the magnetic flux motionless. The dynamics of the magnetic flux interaction with superconductors is controlled by this property. The cases of electrical transport in a round wire and the magnetization of wires of various shapes (circular, elliptical, plate) in an external magnetic field are analysed. Resistance to the magnetic field penetration means that the field produced by the superconducting magnet is no longer proportional to the supplied current. It also leads to a dissipation of electromagnetic energy. In conductors with unequal transverse dimensions, such as flat cables, the orientation with respect to the magnetic field plays an essential role. A reduction of magnetization currents can be achieved by splitting the core of a superconducting wire into fine filaments; however, new kinds of electrical currents that couple the filaments consequently appear. Basic formulas allowing qualitative analyses of various flux dynamic cases are presented.