Simulation of temperature and magnetic field distribution in superconducting bulk during pulsed field magnetization
Simulation of temperature and magnetic field distribution in superconducting bulk during pulsed field magnetization
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DOI：
10.1088/0953-2048/23/10/105021
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发表时间：
2010-10-01
影响因子：
3.6
通讯作者：
Naito, Tomoyuki
中科院分区：
文献类型：
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作者：
Fujishiro, Hiroyuki;Naito, Tomoyuki
对脉冲磁场作用下低温冷却超导块材圆盘的电磁场和温度场进行了理论模拟。模拟结果定性地再现了体表面上的俘获场B（z）和温度T随时间和外加场的变化关系的实验结果。对于具有τ = 0.01 s的上升时间的磁脉冲应用，由于块体的低热导率，磁通量传播比热传播快大约两个数量级。结果表明，由于温升延迟，侵入磁通逃逸。对于τ = 1或10 s的较长磁脉冲应用，通量传播速度变慢并接近热传播速度。在这种情况下，可归因于磁通蠕动的磁通逃逸变小，并且可以实现更高的俘获场。讨论了利用脉冲场磁化提高俘获场的方法。
A theoretical simulation of electromagnetic and thermal fields was performed for a cryocooled superconducting bulk disc after applying a magnetic pulse. The results of the simulation qualitatively reproduced the experimental ones for the time and applied field dependences of the trapped field B(z) and the temperature T on the bulk surface. For magnetic pulse application with a rise time of tau = 0.01 s, the magnetic flux propagation was about two orders of magnitude faster than the heat propagation because of the low thermal conductivity of the bulk. The results show that the intruding magnetic flux escaped because of the delayed temperature rise. For a longer magnetic pulse application with tau = 1 or 10 s, the flux propagation speed becomes slow and approaches the heat propagation speed. In this case, the magnetic flux escape attributable to the flux creep becomes small and a higher trapped field can be achieved. The method of exploring the enhancement of the trapped field using pulsed field magnetization is discussed.