Research on Electrical Breakdown Mechanism in Gaseous Mixtures by Controlling Pulsed Laser Irradiation with Quantum Effect.

本文采用脉冲激光控制放电调制的方法，研究了电绝缘气体的闪蒸机理。我们的研究对象大致分为以下四个项目：(1)用脉冲激光诱导等离子体法观察介电气体中的电子和离子行为及其带电粒子输运系数的测量。(2)用脉冲激光触发法控制直流电压下的正流光及其在空间电荷电场测量中的应用。(3)常压下含氮气气体的放电特性及脉冲激光放电控制方法的电火花放电机理研究。(4)脉冲激光静电沉积与消除技术的发展。从这些项目中，我们证实了脉冲激光产生的具有量子效应的电离等离子体能够在一定的时空间隔内控制放电过程，并且非常有效地阐明了各种绝缘气体的火花机理。主要取得了以下重要成果：(1)在常压下绝缘气体中带电粒子输运系数的测量一直是困难的，而我们利用脉冲激光的方法使其成为可能。(2)对直流电晕放电条件下离子流区空间电荷电场进行了测量，结果与数值分析结果吻合较好。(3)具有电晕稳定作用的火花在一定放电条件下的耐压只能由脉冲激光照射决定。

In this work, the method of discharge modulation controlled by a pulsed laser was used to investigate sparkover mechanism of electrical insulation gas. Our research objects were divided roughly into four projects as follows, (1)Observation of electron and ion behaviors in dielectric gases using a pulsed laser-induced plasma method and measurement of transport coefficients for their charged particles. (2)Positive streamer control under dc voltage using pulsed laser-triggering method and it's application to the measurement of space charge electric field. (3)Sparkover discharge characteristics in gas mistures with N_2 at atmospheric pressure and research on electrical sparkover mechanism using pulsed laser-discharge control method. (4)Development of the static charge depositing and eliminating technique by pulsed laser.From these projects, we confirmed that the ionizing plasma produced by a pulsed laser with quantum effects is able to cotrol the discharge processes for a space-time interval and extremely effective to make clear sparkover mechanism for various insulation gases. In paticular, it was taken the important results as follows, (1)Until now, transport coefficient of the charged particle was difficult to measure in insulation gasese at atmospheric presure, but our method with a pulsed laser made it possible to realize it. (2)Space charge electric field in ion flow region under DC corona discharge was measured, and it's result in good agreement with a result of numerical analysis was confirmed. (3)Withstand voltage of sparkover with corona stabilization action under a crtain discharge condition can be decided only by a pulsed laser irradiation.