外界磁场对两种YBCO超导带材临界电流及n值影响分析

Influence of Background Magnetic Field on Critical Current and n Value of Two Kinds of YBCO Tapes

为掌握钇钡铜氧(YBCO)高温超导带材在不同种类和大小的外界磁场环境下的基本特性,针对AMSC和Superpower制备的两种不同的YBCO超导带材(超导带材Ⅰ和Ⅱ)在不同磁场强度及角度下的Ic及n值进行实验测量和计算,分析了外界磁场变化对Ic及n值的影响。采用在液氮环境下改变超导带材的外界磁感应强度及角度(0～0.9T,0～90°),在交直流背景磁场下,应用直流超导电源给超导带材加载流并测量带材两端的电压,获得两种YBCO高温超导带材的Ic(1μV/cm)及n值(0.1～1.5μV/cm)。由实验结果可知,虽然两种超导带材的Ic及n值都随外界磁场强度的增大而减小,但是无论是在直流背景磁场还是在交流背景磁场下,带材表面与磁场的夹角对超导带材Ⅰ特性的影响要小于超导带材Ⅱ,超导带材Ⅰ的稳定性要好于超导带材Ⅱ。

To master the basic characteristics of yttrium barium copper oxygen（YBCO） high temperature superconducting tapes in different types and intensity of background magnetic field.This paper focuses on AMSC and Superpower preparation of two different YBCO superconducting tapes（superconducting tapeⅠ and Ⅱ）,Ic and the n value in different magnetic field intensity and angles are measured and calculated,and then analyses the effect of background magnetic field on the Ic and n values.Under the liquid nitrogen environment and changing background magnetic flux density and angle of the superconducting tape（s 0～0.9T,0～90°）.Under the background of AC and DC magnetic field,applying DC load flow with DC superconducting power supply and measure both sides voltage of superconducting tapes.Obtain the Ic（1μV/cm）and n values（0.1～1.5μV/cm）of two kinds of YBCO high temperature superconducting tapes.From the experimental results,although Ic and the n value of two different superconducting tapes decrease with the increase of background magnetic field intensity,but both in DC magnetic field and in AC magnetic field,tape surface angle to the magnetic field effect on the characteristics of superconducting tapes Ⅰ less than their effect on superconducting tapes Ⅱ,so stability of superconducting tape Ⅰ is better than superconducting tape Ⅱ.