Compton散射下超强激光等离子体通道的演化

应用多光子非线性Compton散射模型、空间动态补偿模型、非线性薛定谔方程和数值模拟方法,研究了Compton散射对超强飞秒激光等离子体中通道的影响,提出了将Compton散射光作为形成等离子体通道的新机制,给出了超强飞秒激光脉冲在等离子体中传播和电子密度随时间变化的非线性修正方程,并进行了数值模拟.研究发现:散射使等离子体中电子密度峰值增大1个量级,半径增大1 mm.激光最大功率密度被限制在10~(18)W/m~2以下,随传输距离增大缓慢衰减.传输初始阶段,单脉冲衰减能量较散射前增大2%,之后衰减较平缓.通过增加超强飞秒激光脉冲输入功率,能有效地增加电子密度峰值,有利于等离子体通道的形成.并对所的结论给出了初步物理解释.

Channel evolution of extra-intense laser plasma under Compton scattering

By using the model of multi-photon nonlinear Compton scattering, the model of space dynamic compensation, nonlinear Schrödinger equation and numerical simulation means, the influence of the channel in the extra-intense femo-second laser-plasma produced by Compton scattering was studied, a new mechanism of the plasma channel formed by Compton scattering optical was given, the nonlinear amended equations on the propagation of the extra-intense femo-second laser pulse in the plasma and the changing of the electron density along time had been given out, and the equations were simulated with the values. The results show that the one order of magnitude of the crest value of the electron density in the plasma was increased by Compton scattering than before the scattering, and the 1mm creased number of the radius was produced. The maximum laser power density was limited under 1018W/m2, and it was slowly decreased along increasing of the propagation distance. The 2% decreased energy of the simple pulse was produced than the scattering in the initial propagation stage, and after, the decreasing was mild. The crest value of the electron density was affectively increased through the increasing of the import power of the extra-intense femo-second laser pulse, and the means is good to the forming of plasma channel. Then, the initial physics explaining on the results were given out.