The voltage signal on a superconducting wire in AC transport

Abstract

The behaviour of a hard superconductor with a rectangular cross-section, transporting AC, is studied by means of the analysis of the accompanying voltage signal. In particular, we compare the electrical signal that would appear on a conductor with square cross-section with the predictions derived from the analytical models for a round wire and a thin strip. In contrast to similar works focused on the AC loss issue, ours involves the analysis of the voltage waveform, in particular the third and fifth harmonic components. Surprisingly, the critical state based numerical calculations yielded a voltage waveform that is very similar to the one derived for a round wire. However, after including the flux creep, the shape of the voltage waveform changed substantially. This also means that the study of higher harmonics could be a powerful tool in the investigation of AC transport in real superconducting conductors.