Measurement of Transport Characteristics in HTS Conductors With Large Current Capacity by Using an HTS Current Transformer

In order to quantitatively elucidate the transport characteristics of HTS conductors with large current capacities, we minutely investigated the relation between the current distributions in the sample conductor and the circuit parameters such as joint resistance and sample inductance. A high temperature superconducting current transformer (HTS-CT) was used to energize a large current in the sample conductor. No change in the joint resistance was observed with an increase of the sample current. On the other hand, the current ratio of the HTS-CT decreased with an increase in the sample current. This is considered to be equivalent to the inductance becoming large with an increase in the sample current. From the measured current distributions, we see that the current in the central area of the conductor is increased with increasing sample current. Based on these experimental results, the relation between the change of the current distributions and the increase of the sample inductance is discussed.