Guiding large-scale spark discharges with ultrashort pulse laser filaments
Guiding large-scale spark discharges with ultrashort pulse laser filaments
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DOI：
10.1063/1.373710
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发表时间：
2000-07-15
影响因子：
3.2
通讯作者：
Mercure, HP
中科院分区：
文献类型：
--
作者：
La Fontaine, B;Comtois, D;Mercure, HP
利用超短激光脉冲在空气中的非线性传播特性，我们能够产生长的电离细丝，用于引导火花放电。用20 mJ的激光脉冲能量，产生一个或两个电离细丝，并可以引导流注放电超过2 m的空气间隙，其中电场是相当均匀的，平均值为0.6 MV/m。在激光脉冲产生电离细丝后，观察到1-3 μ s的时间的这种引导效应。较长的延迟（10-15 μ s）记录在较高的激光脉冲能量，与大量的灯丝。图像的早期阶段的放电的均匀的空气间隙显示，激光产生的电离丝不启动的放电过程，而是作为首选的通道，其中的领导人的增长是加速。最后，当差距中的电压击穿时，这些直的导电通道承载电弧电流。(C)2000年美国物理学会。[S0021-8979（00）06214-9]。
Using the nonlinear propagation properties of ultrashort laser pulses in air, we were able to produce long ionized filaments that served to guide spark discharges. With a laser pulse energy of 20 mJ, one or two ionized filaments were created and could guide streamer discharges over 2 m air gaps, where the electric field was fairly uniform and had an average value of 0.6 MV/m. Such a guiding effect was observed for times of 1-3 mu s after the laser pulse created the ionized filaments. Longer delays (10-15 mu s) were recorded at higher laser pulse energy, with a larger number of filaments. Images of the early stages of the discharge of a uniform air gap show that the laser-produced ionized filaments do not initiate the discharge process but act rather as preferred channels where the leader growth is accelerated. In the end, these straight conductive channels carry the arc current as the voltage in the gap breaks down. (C) 2000 American Institute of Physics. [S0021-8979(00)06214-9].