BS EN 61788-1-2007 超导性.临界电流测量.铌-钛复合超导体的直流临界电流

标准号：BS EN 61788-1-2007
中文标准名称：超导性.临界电流测量.铌-钛复合超导体的直流临界电流
英文标准名称：Superconductivity - Critical current measurement - D.C. critical current of Nb-Ti composite superconductors
标准类型：H63
发布日期：2007/2/28 12:00:00
实施日期：2007/2/28 12:00:00
中国标准分类号：H63
国际标准分类号：29.050
引用标准：IEC 60050-815
适用范围：This part of IEC 61788 covers a test method for the determination of the d.c. critical current of either Cu/Nb-Ti composite superconductors that have a copper/superconductor ratio larger than 1 or Cu/Cu-Ni/Nb-Ti wires that have a copper/superconductor ratio larger than 0,9 and a copper alloy (Cu-Ni)/superconductor ratio larger than 0,2, where the diameter of Nb-Ti superconducting filaments is larger than 1 μm. The changes for the Cu/Cu-Ni/Nb-Ti are described in Annex C. The Cu-Ni uses all of the main part of the standard with the exceptions listed in Annex C that replace (and in some cases are counter to) some of the steps in the main text.This method is intended for use with superconductors that have critical currents less than 1 000 A and n-values larger than 12, under standard test conditions and at magnetic fields less than or equal to 0,7 of the upper critical magnetic field. The test specimen is immersed in a liquid helium bath at a known temperature during testing. The test conductor has a monolithic structure with a round or rectangular cross-sectional area that is less than 2 mm2.The specimen geometry used in this test method is an inductively coiled specimen. Deviations from this test method that are allowed for routine tests and other specific restrictions are given in this standard.Test conductors with critical currents above 1 000 A or cross-sectional areas greater than 2 mm2 could be measured with the present method with an anticipated increase in uncertainty and a more significant self-field effect (see Annex B). Other, more specialized, specimen test geometries may be more appropriate for larger conductor testing which have been omitted from this present standard for simplicity and to retain a lower uncertainty.The test method given in this standard is expected to apply to other superconducting composite wires after some appropriate modifications.