Commercial high-$T_{\mathrm{c}}$ superconducting (HTS) coated conductors exhibit asymmetric $I_{\mathrm{c}}(B,\theta )$ characteristics, where $B$ presents a DC magnetic field and $\theta$ is defined as the angle between an applied magnetic field and the normal component of the superconductor plane. The asymmetric $I_{\mathrm{c}}(B,\theta )$ characteristics have a non-trivial influence on the dominant loss component, magnetization loss, of various HTS applications where HTS conductors are exposed to an AC magnetic field. Here, we present measurements of $I_{\mathrm{c}}(B,\theta )$ and magnetization loss in a 12 mm-wide (Rare Earth)Ba${}_2$Cu${}_3$O${}_{7-\mathrm{d}}$ (REBCO) commercial coated conductor at 77, 70, and 65 K. In the $I_{\mathrm{c}}(B,\theta )$ measurement, $\theta$ was varied around a full 360${}^{°}$ revolution and $B$ was varied up to 0.2 T. In terms of the magnetization loss measurement, the applied AC magnetic field amplitude is up to 110 mT and the field angle varied from 0${}^{°}$ to 180${}^{°}$. At the three given temperatures, we observed magnetization loss variations among the field-angle range, in particular, for $\theta$ and 180${}^{°}$-$\theta$, which are in mirror symmetry relative to the superconducting plane. Furthermore, this asymmetric field-angle dependence of the magnetization loss becomes more apparent at higher applied field amplitudes and lower operating temperatures. A finite element method simulation using H-formulation was carried out by directly interpolating the measured $I_c(B,\theta )$ data, and the simulation results reproduce the trend of the experimental results. We also found that the magnetization loss is not equivalent within the positive and negative half field cycles due to the asymmetric $I_{\mathrm{c}}(B,\theta )$ characteristics of the conductor. Numerical simulations revealed a clear correlation between the magnetization loss and the asymmetric $I_{\mathrm{c}}(B,\theta )$ data for the whole 360${}^{°}$ field-angle range in the REBCO conductor. The asymmetry in the $I_{\mathrm{c}}(B,\theta )$ data about the ab-peak causes differences in magnetization loss values for the mirror-symmetric field angles. The asymmetry in the $I_{\mathrm{c}}(B,\theta )$ data upon field reversal also results in differences between magnetization loss values for the positive and negative cycles.

中文翻译：

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不同温度下不对称临界电流对 (RE)Ba2Cu3O7−d 涂层导体磁化损耗特性的影响

商业高${吨}_{\mathrm{C}}$ 超导 (HTS) 涂层导体表现出不对称 ${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$ 特征，其中 $乙$ 呈现直流磁场和 $\theta$定义为外加磁场与超导体平面法向分量之间的夹角。不对称的${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$在 HTS 导体暴露于交流磁场的各种 HTS 应用中，这些特性对主要损耗分量、磁化损耗有重要影响。在这里，我们提供测量${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$ 和 12 mm 宽（稀土）Ba 中的磁化损失${}_2$铜${}_3$哦${}_{7-\mathrm{d}}$ (REBCO) 商用涂层导体，温度为 77、70 和 65 K。 ${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$ 测量， $\theta$ 围绕一个完整的 360 度变化${}^{°}$ 革命和 $乙$ 变化高达 0.2 T。 在磁化损耗测量方面，施加的交流磁场幅度高达 110 mT，场角从 0${}^{°}$ 到 180${}^{°}$. 在三个给定温度下，我们观察到了场角范围内的磁化损耗变化，特别是对于$\theta$ 和 180${}^{°}$——$\theta$，它们相对于超导平面镜像对称。此外，磁化损耗的这种不对称场角依赖性在较高的外加场幅度和较低的工作温度下变得更加明显。使用H公式的有限元方法模拟是通过直接插值测量的${\mathrm{一世}}_C(乙,\theta )$数据，模拟结果再现了实验结果的趋势。我们还发现，由于不对称，正负半场周期内的磁化损耗并不相等。${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$导体的特性。数值模拟揭示了磁化损耗与非对称性之间的明显相关性${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$ 整个360的数据${}^{°}$REBCO 导体中的场角范围。中的不对称${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$关于 ab 峰值的数据导致镜像对称场角的磁化损耗值存在差异。中的不对称${\mathrm{一世}}_{\mathrm{C}}(乙,\theta )$ 磁场反转数据也会导致正循环和负循环的磁化损耗值之间存在差异。