ENHANCEMENT OF MAGNETORESISTANCE DUE TO HALL CURRENT IN ALUMINUM - COPPER COMPOSITE

Enhancement of magnetoresistance due to a Hall current is discussed. If an interface between different materials exists in a cable, a non-uniform Hall effect may yield a Hall current across the interface. Such a current causes an additional resistive loss, and an enhanced magnetoresistance should be observed. Since the polarity of the Hall effect in copper is opposite to that in aluminium, the effect might be conspicuous in an Al-Cu composite. Enhanced resistivity is calculated in a short circuit model, where the basic mechanism is easily understood, and next in a coaxial model, which is for a particular but realistic model of a cable. A basic method for evaluation of enhanced resistivity is established for the composite conductor. The reduction of the Hall current is particularly important for the application of a highly conductive material to stabilizers of a superconducting cable.