AC loss characteristics of stacked conductors composed of HTS coated conductors with magnetic substrates

HTS coated conductors (CC's) with substrates of magnetic materials such as Ni-alloys are expected to be promising for practical applications because Ni-alloys are well-texturized by simple processes and production costs of the conductors are significantly reduced. In the former works, it was shown by experiments that HoBaCuO-123 CC's with Ni-alloy substrates exhibit higher AC transport current losses than CC's with non-magnetic Hastelloy substrates. In this work, the AC transport current loss characteristics of stacked conductors composed of a pair of HoBCO CC's with Ni-alloy substrates are experimentally investigated to study a method to suppress the AC transport current losses. It is found that AC transport current losses can be reduced in the stack arrangement by the minimization of influence of the magnetism of the substrates canceling self-fields in the substrates.