超导性.第8部分:交流电损耗测量.用拾波线圈法在液氮温度下测量暴露于横向交流磁场中循环超导导线的交流电总损耗量

[中文适用范围]： IEC 61788的本部分规定了暴露于横向交变磁场的复合超导线材中采用拾波线圈法测量总交流损耗的方法。损耗可能包括磁滞损耗、耦合损耗和涡流损耗。 IEC 61788-13 [2] 中规定了仅测量直流或低扫描速率磁场中磁滞损耗的标准方法。在预计主要用于脉冲线圈和交流线圈应用的金属和氧化物圆形超导线中，交流损耗是由时变磁场和/或电流的应用产生的。磁场对交流损耗的贡献在线圈应用的常用电磁配置中占主导地位。对于暴露于横向交变磁场的超导线材，本方法通常可用于在液氦温度下测量高达商业水平50/60 Hz的宽频率范围内的总交流损耗。对于细丝超导线材，用本方法测得的交流损耗可分为单根细丝的磁滞损耗、细丝间的耦合损耗和常导部分的涡流损耗。如果电线没有厚的正常导电外护套，则主要成分是磁滞损耗和耦合损耗，通过将前一部分估计为低频区域中每周期交流损耗到零频率的外推水平，其中每个周期的耦合损耗与频率成正比。 [外文原描述]： IEC 61788-8:2010 specifies the measurement method of total AC losses by the pickup coil method in composite superconducting wires exposed to a transverse alternating magnetic field. The losses may contain hysteresis, coupling and eddy current losses. The standard method to measure only the hysteresis loss in DC or low-sweep-rate magnetic field is specified in IEC 61788-13. In metallic and oxide round superconducting wires expected to be mainly used for pulsed coil and AC coil applications, AC loss is generated by the application of time-varying magnetic field and/or current. The contribution of the magnetic field to the AC loss is predominant in usual electromagnetic configurations of the coil applications. For the superconducting wires exposed to a transverse alternating magnetic field, the present method can be generally used in measurements of the total AC loss in a wide range of frequency up to the commercial level, 50/60 Hz, at liquid helium temperature. For the superconducting wires with fine filaments, the AC loss measured with the present method can be divided into the hysteresis loss in the individual filaments, the coupling loss among the filaments and the eddy current loss in the normal conducting parts. In cases where the wires do not have a thick outer normal conducting sheath, the main components are the hysteresis loss and the coupling loss by estimating the former part as an extrapolated level of the AC loss per cycle to zero frequency in the region of lower frequency, where the coupling loss per cycle is proportional to the frequency. This second edition cancels and replaces the first edition published in 2003. This edition constitutes a technical revision. The main changes with respect to the previous edition are listed below: - extending the applications of the pickup coil method to the a.c. loss measurements in metallic and oxide superconducting wires with a round cross section at liquid helium temperature, - using the word "uncertainty" for all quantitative (associated with a number) statistical expressions and eliminating the quantitative use of "precision" and "accuracy". Key words: superconductivity, TC90