Growing momentum in improvement of high-temperature superconducting wire performance

There has recently been an accelerating trend toward improving the performance of high-temperature superconducting wire materials. This trend is likely to give a strong boost to practical application of high-temperature superconducting equipment. Sumitomo Electric Industries, Ltd. announced February 10 that it has succeeded in increasing the critical current (the maximum current that can flow through a superconductor) of its bismuth (Bi)-based superconducting wire from previous 180 A to 200 A, and has confirmed its capacity and readiness to proceed to commercial production. On the same day, Fujikura Ltd. also announced that it has developed an yttrium (Y)-based superconducting wire with a length of 816.4 meters and critical current of 572 A, setting a new world record for IcL value (product of length and critical current).

Sumitomo Electric Industries has been selling Bi-based superconducting wires since 2004. While the company has already developed a superconducting wire with a critical current of 200 A in 2006, it has now established mass production technology for the product. The company plans to start mass production by this spring. The higher the critical current of superconducting wire, the smaller superconducting equipment can be designed.

Meanwhile, Fujikura succeeded in stabilizing the quality of its Y-based superconducting wires by employing a new heat treatment method in the process of forming the superconducting layer. The company intends to continue improving its products to achieve a greater length, higher performance and lower cost, and aims to develop a new superconducting wire with a length of 1,000 meters and critical current of 1,000 A by 2012.

Source: The Denki Shimbun (The Electric Daily News)