Magnetization Anomaly of ${\rm Nb}_{3}{\rm Al}$ Strands and Instability of ${\rm Nb}_{3}{\rm Al}$ Rutherford Cables
Magnetization Anomaly of ${\rm Nb}_{3}{\rm Al}$ Strands and Instability of ${\rm Nb}_{3}{\rm Al}$ Rutherford Cables
复制标题
${ m Nb}_{3}{ m Al}$ 股线的磁化异常和 ${ m Nb}_{3}{ m Al}$ 卢瑟福电缆的不稳定性
DOI：
10.1109/tasc.2007.898169
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发表时间：
2007
影响因子：
1.8
通讯作者：
M. Wake
中科院分区：
文献类型：
--
作者：
R. Yamada;A. Kikuchi;M. Wake
费米实验室和NIMS合作，使用具有Nb基体的Cu稳定股线，制造了30米长的卢瑟福电缆。最近对钢绞线和电缆进行了测试。在这两种情况下，在1.5特斯拉左右观察到不稳定性。首先使用平衡线圈磁力计在4.2K下测量该股的磁化强度。股线在1.6 T附近表现出非常大的磁化行为，这远高于通常的Nb基体（4.2 K）。将该结果与使用SQUID磁力计的短股样品的磁化数据进行比较，其中在0.5特斯拉下观察到通量跳变信号，但在更高的场下未观察到。为了解释这种磁化异常，丝间耦合通过薄Nb膜在股线由于邻近效应，这是防止外部磁场的完全渗透到股线的内部部分，建议。在卢瑟福电缆的低场区域中观察到的不稳定性问题和用该电缆缠绕的小型跑道磁体归因于这种效应。
Using a Cu stabilized strand with Nb matrix, a 30 meter long Rutherford cable was made by a collaboration of Fermilab and NIMS. Recently the strand and cable were tested. In both cases instability was observed at around 1.5 Tesla. The magnetization of this strand was measured first using a balanced coil magnetometer at 4.2 K. Strands showed an anomalously large magnetization behavior around at 1.6 T, which is much higher than the usual (4.2 K) of Nb matrix. This result is compared with the magnetization data of short strand samples using a SQUID magnetometer, in which a flux-jump signal was observed at 0.5 Tesla, but not at higher field. To explain this magnetization anomaly, the interfilament coupling through the thin Nb films in the strands due to the proximity effect, which is preventing the full penetration of the external field into the inside part of strand, is suggested. The instability problems observed in low field regions of the Rutherford cables and the small racetrack magnet wound with this cable are attributed to this effect.