激光触发真空开关光谱和导通特性实验研究

为了研究激光触发真空开关的靶材激光诱导击穿光谱和电弧光谱，分析影响时延抖动的微观因素，利用单脉冲纳秒激光轰击位于开关阴极的靶材激发等离子体，采用滤光片和光电倍增管组合使用的方法，取得了离散波长光强的数据，建立拟合曲线，进行了理论分析。结果表明，脉冲激光能量增大可以提高靶材激光诱导击穿光谱的强度，但几乎不影响电弧光谱的强度；增大开关两端电压可以提高电弧光谱强度；在开关强电场作用下，电弧等离子体碰撞激发，等离子体的成分比例随电压大小发生变化；时延抖动与电压大小无关，与自由电子运动状态和电弧离子种类无关，主要在触发阶段受影响，而相比激光能量，开关电压大小对导通时的电压下降沿陡度起主要作用。这一结果对激光触发真空开关中激光与靶材相互作用、脉冲电弧和时延抖动的进一步研究是有帮助的。

Experimental study on spectrum and conduction properties of laser triggered vacuum switch

In order to study laser-induced breakdown spectroscopy ( LIBS ) and arc spectrum of laser-triggered vacuum switch( LTVS) , and analyze the micro factors affecting delay jitter. By using single-pulse ns laser to bombard the target plasma located on switch cathode and the combined method of photoelectric multiplier tube and optical filters, the data of light intensity of discrete wavelengths and the fitting curve were gotten. After theoretical analysis, the results show that the increase of the pulsed laser energy could improve the strength of target LIBS, but almost don' t affect the strength of arc spectrum. The increase of switch voltage can improve the intensity of arc spectrum. Arc plasma collides and excites in the strong electric field at the switch. The ingredient proportion of plasma changes with the change of voltage. Jitter is independent of voltage magnitude, motion status of free electrons and races of arc plasmas. The main affection takes place in the triggering period. Not laser energy but switch voltage plays a major role in the steepness of voltage drop. The results are useful for the further study about laser-target interaction, pulsed-arc and delay-jitter of LTVS.