氘化物阴极真空弧放电光斑分布

氘化物真空弧放电在许多领域均有应用，如无损检测、石油探井、中子活化分析等。和金属阴极不同，氘化物阴极放电时会释放大量的气体分子，表现出许多不同性质。采用放大镜头和ICCD相机观察了氘化物阴极真空弧放电光斑分布。测量系统的空间分辨率约为5 μm，时间分辨率最小2 ns。放电脉冲半高全宽（FWHM）0.9 μs，弧流波形为半周期正弦波。实验结果表明，氘化物真空弧放电时，所有阴极斑聚集为一个群落，表现为一个大光斑；在液滴作用下，阴极斑群落偶尔也会分裂为两个或多个群落；光斑形状不受弧流影响，但面积和亮度会随弧流增加而增大。氘化物阴极放电斑点聚集有利于产生高密度等离子体，提高放电效率。

Luminous spot distribution of vacuum arc discharge with deuteride cathode

Vacuum arc discharges with deuteride cathode have many applications, such as nondestructive examination, oil logging, and neutron activation analysis. Deuteride cathode releases many gases during discharge, which is quite different from metal cathode. The discharges display some unique characteristics. A maguifying lens and an ICCD camera are used to observe the luminous spots of vacuum arc discharge. The space resolution of this system is about 5 μm, and the time resolution is about 2 ns. The arc current has a full width at half maximum (FWHM) of about 0.9 μs, and its waveform is half cycle sinusoidal. The results show that the luminous spots merge together into a big one in most cases. Sometimes there are two or more luminous spots due to droplets. The area of the luminous spot grows as arc current increases. The cathode spots’ merging is helpful to increase plasma density and improve discharge efficiency.