Self-Field Effects in Magneto-Thermal Instabilities for Nb-Sn Strands
Self-Field Effects in Magneto-Thermal Instabilities for Nb-Sn Strands
复制标题
Nb-Sn 线材磁热不稳定性的自场效应
DOI：
10.1109/tasc.2008.921899
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发表时间：
2008
影响因子：
1.8
通讯作者：
A. Zlobin
中科院分区：
文献类型：
--
作者：
B. Bordini;E. Barzi;S. Feher;L. Rossi;A. Zlobin
最近的进展，在临界电流密度的导体，再加上一个大的有效灯丝尺寸，引起了人们的注意，磁热不稳定性的问题。在低磁场下，由于上述不稳定性，这种高股线的失超电流显著低于它们的临界电流。本文提出了一个绝热模型来计算由于磁热不稳定性而导致的最小电流。该模型是基于一个dasiaintegralpsila方法已经在其他地方使用。相对于以前的模型的主要区别是增加了自场效应，允许描述非磁化股线的过早失超，并更好地计算强磁化股线的失超电流。该模型是在4.2 K在费米实验室获得的实验结果，使用处女改性果冻卷（MJR）股与低残余电阻率比（RRR）的稳定铜是在良好的协议。在1.9 K的预测模型和在欧洲核子研究中心进行的测试结果，在4.2 K和1.9 K，在0.8 mm棒再堆叠过程（RRP）股与低RRR值进行了讨论。在1.9 K下，测试揭示了在低场下的意想不到的链性能，这可能是新的稳定性制度的标志。
Recent advancements in the critical current density of conductors, coupled with a large effective filament size, have drawn attention to the problem of magneto-thermal instabilities. At low magnetic fields, the quench current of such high strands is significantly lower than their critical current because of the above-mentioned instabilities. An adiabatic model to calculate the minimum current at which a strand can quench due to magneto-thermal instabilities is developed. The model is based on an dasiaintegralpsila approach already used elsewhere . The main difference with respect to the previous model is the addition of the self-field effect that allows to describe premature quenches of non-magnetized strands and to better calculate the quench current of strongly magnetized strands. The model is in good agreement with experimental results at 4.2 K obtained at Fermilab using virgin Modified Jelly Roll (MJR) strands with a low residual resistivity ratio (RRR) of the stabilizing copper. The prediction of the model at 1.9 K and the results of the tests carried out at CERN, at 4.2 K and 1.9 K, on a 0.8 mm Rod Re-Stack Process (RRP) strand with a low RRR value are discussed. At 1.9 K the test revealed an unexpected strand performance at low fields that might be a sign of a new stability regime.