arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1407.8019physics.plasm-ph
收藏

超相对论电子组态中多拍瓦飞秒laser脉冲尾流场的动力学

Dynamics of the wakefield of a multi-petawatt, femtosecond laser pulse in a configuration with ultrarelativistic electrons

D. Jovanovic, R. Fedele, M. Belic

摘要:

在非磁化等离子体中,由多拍瓦,飞秒,煎饼形状的激光脉冲的尾场激发的解析和数值描述的制度与超相对论电子抖动速度,当等离子体电子几乎被驱逐出脉冲区域。这是第一次在流体理论中实现。设计了一种新颖的数学模型,与使用激光场包络和有质动力引导中心平均的标准方法相反,该模型不会因非常强的泵浦强度而崩溃。这是通过采用三个时间尺度的描述来实现的,其中中间尺度与电磁波的非线性相位以及其波前的弯曲相关联。脉冲的演变和它的静电尾流的研究,在一个二维的几何形状,与斑点直径\geq 100微米的数值解。它表明,最佳的初始脉冲长度需要略大于1微米(1-2振荡),建议由简单的分析本地估计,因为非本地等离子体响应往往会拉伸非常短的脉冲。

英文摘要:

The wake field excitation in an unmagnetized plasma by a multi-petawatt, femtosecond, pancake-shaped laser pulse is described both analytically and numerically in the regime with ultrarelativistic electron jitter velocities, when the plasma electrons are almost expelled from the pulse region. This is done, for the first time, in fluid theory. A novel mathematical model is devised that does not break down for very intense pump strengths, in contrast to the standard approach that uses the laser field envelope and the ponderomotive guiding center averaging. This is accomplished by employing a three-timescale description, with the intermediate scale associated with the nonlinear phase of the electromagnetic wave and with the bending of its wave front. The evolution of the pulse and of its electrostatic wake are studied by the numerical solution in a two-dimensional geometry, with the spot diameter \geq 100 microns. It reveals that the optimum initial pulse length needs to be somewhat bigger than 1 micron (1-2 oscillations), as suggested by simple analytical local estimates, because the nonlocal plasma response tends to stretch very short pulses.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑