A small-scale experiment demonstrating the current lead resistance method of preventing a current imbalance

摘要

In an earlier paper, we proposed the current lead resistance method to avoid a current imbalance, one of the most serious problems in superconducting strands, where the strands of the current lead are insulated from each other, and individually connected to the strands of the superconducting strands. In this paper we report the current lead resistance method to have its validity in an experiment with a small superconducting magnet. The cable of the magnet was composed of seven strands, one central and six surrounding strands, all insulated from each other. The length of the cable was about 400 m, and the inductance of the magnet was around 160 mu H. The experiment was carried out under various conditions, i.e. applying AC or DC voltage and sine or triangle current-wave form from low to high frequencies. In AC operation, the direction of the current in the central strand is opposite to that in the outer strands. With the current lead resistance method, however, the direction and the magnitude of the current in the central strand are the same as those in the outer strands at a low frequency, but not at a high frequency. These results were well consistent with our calculations and proved the principle of the current lead resistance method. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 13]