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气绝缘气体的火花放电机理。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方法观察电介质气体中电子和离子的行为，并测量其带电粒子的输运系数。（2）脉冲激光触发直流正流光控制方法及其在空间电荷电场测量中的应用。（3）大气压下含N_2气体的火花放电特性及利用脉冲激光放电控制方法研究电火花放电机理。（4）脉冲激光沉积和消除静电荷技术的发展，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范围内控制放电过程，对研究各种绝缘气体的放电机理极为有效。主要取得了以下重要结果：（1）大气压下测量带电粒子在绝缘气体中的输运系数是困难的，而我们用脉冲激光的方法实现了这一点：（2）测量了直流电晕放电下离子流区的空间电荷电场，并与数值分析结果进行了比较，两者吻合较好。（3）在一定的放电条件下，具有稳晕作用的火花放电的耐受电压只能由脉冲激光辐照来决定。

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.