Steady-state Hall losses in composite cryogenic conductors

Abstract

Three distinct numerical methods are developed and evaluated for predicting the transverse Hall currents in long composite cryogenic conductors. These methods are applied to three different conductor geometries; a double-strip, a square-jacketed and a round-jacketed conductor. The double-strip geometry is used as a simple example to illustrate the Hall effect in composite conductors and to compare results from the three calculational methods. Earlier experimental results on the anomalous magnetoresistance of square-jacketed Al-Al alloy composite conductors are reanalysed using the present accurate numerical approaches. Improved agreement is obtained between experiment and theory compared with the earlier simplified models. Calculations and experimental data are shown for cases where the applied magnetic field is oriented at an angle with respect to the conductor. The calculated resistance variation with angle is shown to have the same form as the measured data. Good agreement is also obtained between the predictions of the closed-form analytical formulae of Kaneko and Yangai and the present finite element calculations for the Hall currents in Al-Cu round-jacketed composite conductors.