潮湿空气中重频纳秒脉冲流注演变的残余电荷输运机制和调控方法研究

潮湿空气是典型复杂放电环境，调控潮湿空气中重频纳秒脉冲流注放电是低温等离子体前沿研究和应用的迫切需求。然而，高重频脉冲和水分共同作用会导致复杂的流注不稳定现象，本质是残余电荷输运和水分增强的能量弛豫过程。流注演变机理和调控方法尚不完善，极大影响应用的安全性和调控的有效性。本项目针对潮湿空气中重频纳秒脉冲流注演变机理和调控方法开展研究。研究湿度和波形参数对流注演变的影响，揭示潮湿空气中重频纳秒脉冲流注演变的宏观规律；基于激光瞬态电场测量，研究脉冲间隔期空间残余电荷电场的时空演变规律，揭示空间残余电荷输运机制，建立残余电荷输运和流注宏观演变的关联；研究直流偏置和输出阻抗等电源参数对空间残余电荷电场及二次流注约化场强的影响，从残余电荷输运和能量注入角度，建立电源参数对重频纳秒脉冲流注演变的调控模型。通过本项目研究，可掌握潮湿空气中重频纳秒脉冲流注放电演变机理，为脉冲放电等离子体调控提供理论依据。

Humid air is a typical complex discharge environment. Regulation of nanosecond repetitively pulsed streamer discharge in humid air are urgent needs in cutting-edge researches and applications of low-temperature plasma. However, complicated streamer instabilities are induced by both the high-frequency-pulsed excitation and the moisture. The essence of streamer instability is the residual charge transport and the energy relaxation process enhanced by moisture. Streamer evolution mechanisms and regulation methods are not thoroughly understood, which significantly affect the application safety and the regulation efficiency. This project will investigate evolution mechanisms and regulation methods of nanosecond repetitively pulsed streamer discharge in humid air. Impacts of humidity and pulse waveform parameters on streamer evolution will be investigated. Macroscopic evolution patterns of nanosecond repetitively pulsed streamer discharge in humid air will be revealed. Spatial-temporal evolutions of the electric field generated by residual space charges during the pulse interval will be elucidated based on the laser transient electric field measurement. Transport mechanisms of residual space charges will be revealed. Connections between the residual charge transport and the macroscopic streamer evolution will be established. Effects of power source parameters, including the DC bias and the output impedance, on the residual space charge electric field and the reduced electric field of secondary streamer will be determined. Regulation models of power source parameters on nanosecond repetitively pulsed streamer evolution will be established based on residual charge transport and the energy input. Evolution mechanisms and regulation methods of nanosecond repetitively pulsed streamer discharge in humid air will be revealed through this project. Theoretical foundations will be provided for regulation of pulsed discharge plasmas.