Dependence of Dynamic Loss on Critical Current and n-Value of HTS Coated Conductors

The properties of superconductors, such as a critical current and an n-value, have a significant effect on their loss characteristics. This effect is essential for the design of superconducting devices and their loss reduction and, therefore, needs to be thoroughly understood. The dependence of the ac loss in high-temperature superconductors (HTSs) on these properties has been well studied. However, it is still unknown how the dynamic loss is affected. The aim of this article is to address this unsolved problem and provide comprehensive analyses through both numerical simulation and experimental measurements. In this article, HTS coated conductors with a wide range of critical currents and n-values have been extensively studied. Their dynamic losses and resistance under various conditions have been modeled and compared to available experiment measurements. The results clearly show the dependence of the dynamic loss and resistance on the critical current and n-value. The cases with the high current load under strong external magnetic field have been studied as well. All these results show a rapid change of the dynamic loss around certain magnetic fields, which we defined to be the "corner field," Bcor. This article clearly shows the dependence of the dynamic loss and resistance on the critical current and n-value, which can be used as a reference for material selection and design optimization.