强激光与固体靶作用产生的表面电子加速和辐射研究

利用单电子在固体靶表面准静态电磁场中运动的模型和非线性汤姆孙散射理论，研究了以大角度斜入射的强激光照射在固体靶表面产生的沿靶面方向发射的高能超热电子的运动及其产生的电磁辐射脉冲. 数值模拟表明，靶表面的电子在靶面附近的准静态电磁场和反射的激光场中作振荡. 当电子振荡频率接近激光频率时，电子被有效加速，被加速的电子主要沿靶面方向运动并产生向前的阿秒脉冲辐射. 讨论了电子在加速前的不同初始速度分布对辐射脉冲的时间和空间特性的影响，模拟了不同初始状态的多电子相干辐射脉冲的频谱特性. 关键词： 表面准静态电磁场 超热电子 阿秒脉冲 相干辐射

Numerical simulation of acceleration and radiation of surface electrons in the interaction of intense laser pulses with a solid target

The movement and radiation of fast electrons emitting along the surface of a target irradiated by intense laser pulses has been investigated theoretically and numerically by use of the classical theory of Thomson scattering by free electrons in static field. The results indicate that the surface electrons are oscillating in the quasistatic field and the laser field at the beginning. The electrons will be accelerated when their oscillation frequency comes close to the laser frequency, and the attosecond pulse trains and high harmonic are emitted along the surface by surface electrons. The temporal and spatial characteristics of the acceleration and radiation of electrons in different initial states has been compared. The frequency characteristic of the coherent radiation of electron beams are also investigated.