Magnetization, Low Field Instability and Quench of RHQT Nb3Al Strands
Magnetization, Low Field Instability and Quench of RHQT Nb3Al Strands
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RHQT Nb3Al 绞线的磁化、低场不稳定性和淬火
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
V. Velev
中科院分区：
文献类型：
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作者：
R. Yamada;M. Wake;A. Kikuchi;V. Velev
自2005年以来，我们制造并测试了三根RHQT Nb3Al绞线，一根为Nb基体，两根为Ta基体，它们都通过电镀铜完全稳定。当我们用平衡线圈磁力计测量其磁化强度时，我们观察到F1 Nb矩阵股在4.2 K下延伸超过1至1.5特斯拉的巨大磁化曲线。在4.2K下操作的Ta基质链消除了这个问题。但在1.9K时，观察到了类似但较小的反常磁化。我们用有限元方法研究了这些现象。用F1铌矩阵股线，它被解释为在低外部场，在子元件的外层中的内部耦合电流产生屏蔽效应。它降低了内场，保持了内部Nb基体的稳定性，并抵抗超过Nb的Hc的更高的外场。在更高的外场作用下，整个Nb基体的超导电性崩溃并释放出大量的能量，这可能导致大的猝灭。根据股线或电缆中能量的大小，磁体可能会失超，导致低场不稳定性。对用有限元法分析异常进行了一些尝试。
Since 2005, we made and tested three RHQT Nb3Al strands, one with Nb matrix and two with Ta matrix, which are fully stabilized with Cu electroplating. We observed anomalously large magnetization curves extending beyond 1 to 1.5 Tesla with the F1 Nb matrix strand at 4.2 K, when we measured its magnetization with a balanced coil magnetometer. This problem was eliminated with the Ta matrix strands operating at 4.2 K. But with these strands a similar but smaller anomalous magnetization was observed at 1.9 K. We studied these phenomena with FEM. With the F1 Nb matrix strand, it is explained that at low external field, inter-filamentary coupling currents in the outer layers of sub-elements create a shielding effect. It reduces the inside field, keeps the inside Nb matrix superconductive, and stands against a higher outside field beyond the Hc of Nb. At an even higher external field, the superconductivity of the whole Nb matrix collapses and releases a large amount of energy, which may cause a big quench. Depending on the size of the energy in the strand or the cable, a magnet could quench, causing the low field instability. Some attempt to analyze the anomaly with FEM is presented.
Nb3A1 卢瑟福电缆和小型跑道磁铁的淬火测试和 FEM 分析。
DOI：
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发表时间：
2009
期刊：
IEEE Trans.Appl.Supercond. 19
影响因子：
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作者：
A. S. Pirozhkov;M. Kando;et al;R.Yamada;R.Yamada
通讯作者：
R.Yamada