ITER-type low loss Nb3Sn SuperconductorOST is producing wire for the ITER project made with an internal tin process. The wire consists of Nb filaments and tin centers, wrapped with a Ta diffusion barrier, all inside of a high RRR copper jacket. After fabrication is complete, the wire is Cr plated. A typical strand has a nominal diameter of 0.8 mm, and has a Cr coating thickness of 2 microns.
ITER
is an international fusion energy research project involving the EU, and associated third countries such as Switzerland - represented by Euratom, China, India, Japan, South Korea, Russia and USA. Construction, which is expected to last ten years and to cost Euro 5 billion, starts this year in France.
Representative critical current, Jc, and magnetisation data for this type of strand is presented below.
Typical 12 T Jc values exceed 1000 A/mm2, while the hysteresis losses over the non-Cu portion of the conductor are below 1000 mJ/cc.