等离子体密度时演特性(2013,2栏).doc

Compton 散射对飞秒光丝中等离子体密度时演特性的影响郝东山(郑州华信学院信息工程系,河南,新郑 451100 ) 摘要: pton 散射模型、等离子体时间切片模型及数值计算方法,研究了飞秒光丝中等离子体密度的时间演化特性,pton 散射光作为改变等离子体中电子峰值密度的一种新机制,给出了等离子体中带电粒子的动力学修正方程,并进行了数值计算。结果表明:散射使等离子体达到导电的时间缩短,电离区电子密度增长呈准饱和状态,电离衰退区电子密度较缓慢下降,不同脉冲电离贡献率差别缩小。随脉冲切片光强增强,散射使 O 2 电离贡献率有所下降, N 2 电离贡献率最终超过 O 2 电离贡献率, 离子体通道内电子峰值密度增大,高密度等离子体通道寿命延长。在相同峰值强度下,散射使长短脉冲产生的电子密度峰值增长几乎相同,且较散射前有所减小。关键词:非线性光学;飞秒激光成丝;等离子体通道;电子峰值密度;寿命,pton 散射中图分类: 文献标识码: A Influences pton scattering to temporal evolution of plasma density in femto-second light filaments Hao Dongshan ( Department of Information Engineering , Zhengzhou HUaxin University , Xinzheng , Henan 451100 , China ) Abstract By using the multi-photon pton scattering model , plasma time-section model and puting means , influences pton scattering to temporal evolution of plasma density in femto-second light filaments are studied , a new mechanism on the electron crest density in the plasma is changed pton scattering is raised , the amended dynamics equations of charged particle in the plasma have been given out , and the equations puted with the numbers. The results show that the plasma to electricity time is reduced pton scattering , the increases of the electron densities in the ionization area are appeared quasi-saturated points , the electron densities in the ionization decreased area are slowly decreased , and the differences of the ionization contribu