The break of shielding current at pulsed field magnetization of a superconducting annulus (experiment and model simulation)
The break of shielding current at pulsed field magnetization of a superconducting annulus (experiment and model simulation)
复制标题
超导环脉冲场磁化时屏蔽电流的中断（实验和模型模拟）
DOI：
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复制
发表时间：
2016
期刊：
影响因子：
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通讯作者：
A. Kartamyshev
中科院分区：
文献类型：
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作者：
V. Korotkov;E. Krasnoperov;A. Kartamyshev
在液氮中的高Tc环的脉冲场磁化期间，屏蔽电流突然下降，提供磁通量到超导体的孔中的快速穿透。电流中断后，尽管环形体仍保持高度磁化，但孔中的俘获场很小且为负。在目前的工作中，电流开断效果的实验和数值研究。研究了脉冲参数对开断过程中屏蔽电流演变的影响。提出了一个定性描述该过程的简单模型。该模型显示了局部加热的高温超导体环的不均匀性提供了一个高电阻通道的形成与温度接近Tc的发展。这种热通道的出现导致屏蔽电流迅速减小，并呈现出高温下通量跳变的新情况。
During the pulsed field magnetization of a high-Tc annulus in liquid nitrogen the shielding current drops abruptly, providing rapid penetration of the magnetic flux into the hole of the superconductor. After the break of current the trapped field in the hole is small and negative although the body of the annulus remains highly magnetized. In the present work the current breaking effect is investigated both experimentally and numerically. The influence of the pulse parameter on the shielding current evolution during the break is researched. A simple model for the qualitative description of this process is proposed. The model shows the development of heating localized on the inhomogeneity of the high-temperature superconductor annulus providing the formation of a high resistive channel with temperature near to Tc. The appearance of this hot channel leads to the rapid reduction of the shielding current and presents a new scenario of flux jump at high temperature.