A significant advantage for trapped field magnet applications—A failure of the critical state model
A significant advantage for trapped field magnet applications—A failure of the critical state model
复制标题
俘获磁场应用的显着优势——临界状态模型的失败
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
K. Davey
中科院分区：
文献类型：
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作者：
R. Weinstein;D. Parks;R. Sawh;K. Carpenter;K. Davey
正在进行的研究已经将捕获场磁体（TFM）中的可实现场增加到多特斯拉水平。这大大增加了TFM对申请的吸引力。然而，它也增加了TFM的原位活化和再活化的已经非常困难的问题。在大多数应用中使用脉冲零场冷却（ZFC）活化方法，因为它可以用比场冷活化低得多的功率和更普通的设备来完成。半个多世纪以来，临界状态模型（CSM）一直是薄膜材料实验分析和工程设计及其应用的可靠理论工具。CSM预测使用脉冲ZFC将TFM完全磁化至其最大可捕获场BT，max所需的激活场BA为R <$BA/BT，max ≥ 2.0。我们在这里报告的实验R作为一个函数的Jc，发现一个单调下降的R为1.0 Jc的增加。减小到R = 1.0将磁化TFM所需的功率减小了大约一个数量级。这是TFM应用的关键优势。结果还指出了CSM的适用范围的限制，并揭示了从模型中省略的物理。实验结果排除了热效应和钉扎中心几何形状作为R减小的原因。提出了可能的物理原因。
Ongoing research has increased achievable field in trapped field magnets (TFMs) to multi-Tesla levels. This has greatly increased the attractiveness of TFMs for applications. However, it also increases the already very difficult problem of in situ activation and reactivation of the TFMs. The pulsed zero-field-cool (ZFC) method of activation is used in most applications because it can be accomplished with much lower power and more modest equipment than field-cool activation. The critical state model (CSM) has been a reliable theoretical tool for experimental analysis and engineering design of TFMs and their applications for over a half-century. The activating field, BA, required to fully magnetize a TFM to its maximum trappable field, BT,max, using pulsed-ZFC is predicted by CSM to be R ≡ BA/BT,max ≥ 2.0. We report here experiments on R as a function of Jc, which find a monotonic decrease of R to 1.0 as Jc increases. The reduction to R = 1.0 reduces the power needed to magnetize TFMs by about an order of magnitude. This is a critical advantage for TFM applications. The results also indicate the limits of applicability of CSM, and shed light on the physics omitted from the model. The experimental results rule out heating effects and pinning center geometry as causes of the decrease in R. A possible physical cause is proposed.
影响因子：
3.6
作者：
Durrell, J. H.;Dennis, A. R.;Cardwell, D. A.
通讯作者：
Cardwell, D. A.