Properties of niobium-titanium superconducting wires with Nb artificial pinning centers
Properties of niobium-titanium superconducting wires with Nb artificial pinning centers
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DOI：
10.1063/1.362979
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发表时间：
1996-08-01
影响因子：
3.2
通讯作者：
Jablonski, PD
中科院分区：
文献类型：
--
作者：
Heussner, RW;Nunes, CB;Jablonski, PD
人工钉扎中心（APC）的Nb 47重量%的Ti复合线含有24体积%的引脚，其特征在于作为线直径减小。当标称销直径d（p）从165 nm减小到15 nm时，与优化的、常规处理的Nb 47 wt % Ti中的α-Ti带相比，标称圆形销转变成具有相对宽的厚度分布的带。体磁通钉扎力F-p的最大值为25 GN/m（3）（4.2 K，2.5 T），出现在d（p）=40 nm处，此时测得的Nb带厚度范围为1 ~ 16 nm。该F-p值比最好的常规Nb 47重量% Ti中发现的值高约三分之一。通过磁化测量的上临界磁场热，从10.3 T下降到9 T，因为Nb钉变得邻近效应耦合到基质。为了更好地比较APC和常规线材，我们在降低的温度下测量了最佳APC线材的性能，使得其H-c2与Nb 47重量% Ti的H-c2（4.2 K）相同。F-p的峰值在3 T时为36 GN/m（3），几乎是传统Nb-Ti报告的最大值的两倍（类似于5 T时的19 GN/m（3））。尽管钉扎力曲线在较低磁场下保持尖锐峰值，但均衡的5 T临界电流密度为4600 A/mm（2），比常规Nb-Ti的最佳值高约25%。这些性能证明了APC复合材料的强大潜力。(C)1996年美国物理学会。
Artificial pinning center (APC) Nb 47 wt % Ti composite wires containing 24 vol % pins were characterized as the wire diameter was reduced. As the nominal pin diameter d(p) was reduced from 165 to 15 nm, the nominally round pins transformed into ribbons with a relatively wide distribution in thickness, as compared to the alpha-Ti ribbons in optimized, conventionally processed Nb 47 wt % Ti. The maximum in the bulk flux pinning force F-p of 25 GN/m(3) (4.2 K, 2.5 T) occurred at d(p)=40 nm, for which the measured Nb ribbon thickness ranged from 1 to 16 nm. This F-p value was about one third higher than that found in the best conventional Nb 47 wt % Ti. The upper critical magnetic field Heat measured by magnetization, decreased from 10.3 to 9 T as the Nb pins became proximity-effect coupled to the matrix. To better compare APC and conventional wires, we measured the properties of the best APC wire at a reduced temperature so that its H-c2 was the same as H-c2(4.2 K) for Nb 47 wt % Ti. The peak value of F-p was then 36 GN/m(3) at 3 T, almost twice the maximum value yet reported for conventional Nb-Ti (similar to 19 GN/m(3) at 5 T). In spite of the pinning force curve remaining sharply peaked at lower fields, the equalized 5 T critical current density was 4600 A/mm(2), some 25% higher than the best values of conventional Nb-Ti. These properties demonstrate the strong potential of APC composites. (C) 1996 American Institute of Physics.