Experimental study on current re-distribution and stability of multi-strand superconducting cables

Stability of multi-strand superconducting cables against local disturbances should be influenced by the current re-distribution among strands in quench or recovery processes. The current re-distribution and its influence on stability are examined experimentally with two types of three-strand cable. One is made of chrome-plated strands, and another is made of strands with bare-copper surface. A heat pulse is applied to short part of a strand, and normal voltage and current in each strand are measured. The large contact resistance between strands in chrome-plated cable affects the current re-distribution. The minimum heater energy required for quench is measured. The experimental results prove that the stability against local disturbances is improved by the current re-distribution.