强激光脉冲在等离子体通道中的传播及其电子加速

发布时间：2018-06-23 15:00

本文选题：强激光脉冲 + 离子体通道　；参考：《南昌大学》2015年硕士论文

【摘要】：近几十年,激光技术不断完善,特别是超强超短激光脉冲的出现,促进了激光等离子体相互作用的快速发展。首先,激光在等离子体中的稳定传播在实际应用中有重要意义,如激光等离子体加速器,激光核聚变以及高次谐波的产生等,因此激光在等离子体中传播的研究一直是热点。另外,因为高能电子束在惯性约束核聚变中的快点火、高能粒子加速器、X射线的产生等方面有着重要的应用,因此高品质电子束的获取也是激光等离子体研究的热点之一。本学位论文主要探究了激光与等离子体相互作用中两个方面的内容。1、考虑在等离子体尾波场及高阶相对论非线性效应作用下,强激光脉冲在抛物型预等离子体通道中的传播特性。用变分法获得激光的演化方程,数值分析高阶相对论非线性、横向尾波场和纵向尾波场效应对激光脉冲传播的影响规律。2、采用粒子模拟方法,探究在高密度等离子体通道壁中强激光脉冲驱动空泡尾场演化及其电子加速。研究了激光尾波场加速机制转变为等离子体尾波场加速机制的物理过程。研究表明:由于尾波场纵向收缩,激光尾波场加速阶段自注入电子束在尾波场中实现稳相加速;随着激光脉冲的耗散,自注入电子束驱动等离子体尾场进一步捕获并加速通道中的电子,最终获得两群高品质电子束。
[Abstract]:In recent decades, laser technology has been continuously improved, especially the appearance of ultrashort laser pulses, which promotes the rapid development of laser plasma interaction. First of all, the steady propagation of laser in plasma has important significance in practical applications, such as laser plasma accelerator, laser fusion and high harmonic generation, so the research of laser propagation in plasma has been a hot topic. In addition, high energy electron beam has important applications in inertial confinement fusion and X-ray generation of high energy particle accelerator, so the acquisition of high quality electron beam is also one of the hot spots in laser plasma research. In this dissertation, the contents of two aspects of laser plasma interaction are discussed. 1. Under the influence of plasma coda field and high order relativistic nonlinear effect, Propagation characteristics of intense laser pulses in parabolic preplasma channels. The evolution equation of laser is obtained by variational method. The effects of high order relativistic nonlinearity, transverse coda field and longitudinal coda field effect on laser pulse propagation are numerically analyzed. The evolution and electron acceleration of cavitation tail field driven by intense laser pulses in the wall of high density plasma channel are investigated. The physical process of laser coda field acceleration mechanism is studied. The results show that the self-injected electron beam accelerates in the wake field at the acceleration stage due to the longitudinal contraction of the wake field, and with the dissipation of the laser pulse, The self-injected electron beam drives the plasma tail field to further capture and accelerate the electrons in the channel, and finally two groups of high quality electron beams are obtained.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O53;TN249

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