Abstract
To investigate the unbalanced current distribution problem in a high-current capacity superconducting AC/pulse conductor, we have carried out the measurement of the self-inductance of each element wire and the mutual inductances between each element wires in a sub-size conductor for the DPC coil. Substituting these figures into the circuit equations, we have calculated the distributed current of each element wire. The calculated values agree well with the measured current. The dispersions of the measured self-inductances is very small. And, the difference between the self-inductances and the mutual inductance is also very small. In a conventional situation, this extent of small dispersion of the self-inductances can be regarded to be small enough. However, according to our calculation, in a situation of a high-current superconducting AC/pulse conductor, this small deviation generates large current unbalance up to about factor of 3. This result can be explained by the zero resistance of the element wire and the good magnetic coupling between the element wires (k=1), which generate large current unbalance even for the very small unbalance of self-inductances. Meanwhile, it is estimated that the current unbalance is amplified by the outbreak of an electrical contact between two element wires particularly at a point near the end of the conductor.
