We have studied theoretically and experimentally the x-ray production above 1 keV from femtosecond laser plasmas generated on periodically modulated surface targets. Laser energy coupling to plasma surface waves has been modeled using a numerical differential method. Almost total absorption of incident laser radiation is predicted for optimized interaction conditions. Silicon gratings have been irradiated by a 120fs Ti:sapphire laser at irradiances in excess of 1016 W/cm2. X-ray intensities above 1.5 keV (K-shell lines) have been measured as a function of the incidence angle. Results show a distinct x-ray emission maximum for the first order diffraction angle and are in good qualitative agreement with our theoretical predictions.
展开▼
机译:我们在理论和实验上研究了在周期性调制的表面目标上产生的飞秒激光等离子体产生的1 keV以上的x射线。已经使用数值微分方法对耦合到等离子体表面波的激光能量进行了建模。对于最佳的相互作用条件,可以预测入射激光辐射的几乎总吸收。硅光栅已被120fs Ti:蓝宝石激光器以超过1016 W / cm2的辐照度辐照。已经测量了高于1.5 keV的X射线强度(K壳线)作为入射角的函数。结果显示一阶衍射角具有明显的X射线发射最大值,并且与我们的理论预测在质量上吻合良好。
展开▼