Striating of REBCO-Coated Conductors for AC Loss Reduction
Michal Skarba, Marcela Pekarčíková, L Frolek, Eva Cuninková, Martin Necpál, Štefan Šimon
Abstract
Alternating current (ac) losses in superconducting tapes (SCTs) are one of the main concerns for their use in applications where the costs of heat dissipation need to be reduced, such as pulse magnets. Modification of the tapes by striation has been shown to significantly reduce ac losses, and several filamentization methods have been developed. Up to two orders of magnitude decrease in ac losses was reported in previous works with laser ablation, mechanical grooving, or chemical etching. However, a different approach may have to be used to achieve similar results for those SCTs (or their applications after striation), which are more prone to degradation by the side effects of the mentioned methods. We proposed a procedure based on chemo-mechanical etching, which avoids problems arising from thermal degradation and mechanical pressure. Our method intended for the REBCO (RE = rare earth metal, B = Ba, C = Cu, and O = oxygen) based high-temperature SCTs yielded low and reproducible ac losses, low cost, retention of the relative critical current up to 93%, and preservation of the mechanical properties of the tape substrate.