Study of the ionization rate of the released deuterium in vacuum arc discharges with metal deuteride cathodes
Study of the ionization rate of the released deuterium in vacuum arc discharges with metal deuteride cathodes
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DOI：
10.1088/1361-6595/aaa5e0
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发表时间：
2018-01
影响因子：
3.8
通讯作者：
Fei-Xiang Liu;J. Long;Le Zheng;P. Dong;Chen Li;Wei Chen
中科院分区：
文献类型：
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作者：
Fei-Xiang Liu;J. Long;Le Zheng;P. Dong;Chen Li;Wei Chen
通过实验和模型分析，研究了真空电弧放电中金属氘化物阴极释放氘的电离率。实验结果表明，在2-100 A范围内，随着电弧电流的增加，氘的电离率从2%增加到30%。因此，在电弧等离子体模拟中广泛使用的完全电离假设对于低放电电流下释放的氘是不满足的。根据模拟结果，中性离子转换效率为氘穿越阴极斑点区域可以显着小于1，由于快速等离子体膨胀和真空中的稀薄。此外，该模型还揭示了氘原子的电离主要发生在准中性区，而金属原子主要在鞘层区电离并流回阴极，氘原子的电离主要发生在准中性区并向阳极方向移动。因此，阴极鞘层的作用就像一个过滤器，增加了超过鞘区的氘分数。
The ionization rate of the released deuterium from a metal deuteride cathode in vacuum arc discharges is investigated by both experiments and modeling analysis. Experimental results show that the deuterium ionization rate increases from 2% to 30% with the increasing arc current in the range of 2–100 A. Thus the full ionization assumption, as is widely used in arc plasma simulations, is not satisfied for the released deuterium at low discharge current. According to the modeling results, the neutral-to-ion conversion efficiency for the deuterium traveling across the cathodic spot region can be significantly less than one, due to the fast plasma expansion and rarefaction in the vacuum. In addition, the model also reveals that, unlike the metal atoms which are mainly ionized in the sheath region and flow back to the cathode, the deuterium ionization primarily occurs in the quasi-neutral region and moves towards the anode. Consequently, the cathodic sheath layer acts like a filter that increases the deuterium fraction beyond the sheath region.