论文标题
固体在高强度激光照射下观察到的飞秒放牧X射线散射观察到的高强度激光辐照的纳米地下动力学
Nanoscale subsurface dynamics of solids upon high-intensity laser irradiation observed by femtosecond grazing-incidence x-ray scattering
论文作者
论文摘要
观察超快激光诱导的纳米级系统的结构变化对于理解强烈的光结合相互作用的动力学至关重要。对于$ 10^{14} \，\ rm w/cm^2 $的激光强度，在表面上和下方生成高度碰撞的等离子体。随后的运输过程，例如热传导，电子离子热化，表面消融和分辨率发生在Picsecond和Nansecond Time尺度上。成像方法，例如使用X射线自由电子激光器（XFEL），迄今无法通过适当的时间和空间分辨率来测量激光 - 固定相互作用的深度分辨地下动力学。在这里，我们使用XFEL脉冲证明了从激光生产的等离子体中的皮秒放牧X射线散射（GISAXS）。使用多层（ML）样品，通过纳米深度分辨率测量表面消融和地下密度动力学。我们的实验数据挑战了在极端条件下物质的最新建模，并为激光材料处理和高能密度科学打开了新的观点。
Observing ultrafast laser-induced structural changes in nanoscale systems is essential for understanding the dynamics of intense light-matter interactions. For laser intensities on the order of $10^{14} \, \rm W/cm^2$, highly-collisional plasmas are generated at and below the surface. Subsequent transport processes such as heat conduction, electron-ion thermalization, surface ablation and resolidification occur at picosecond and nanosecond time scales. Imaging methods, e.g. using x-ray free-electron lasers (XFEL), were hitherto unable to measure the depth-resolved subsurface dynamics of laser-solid interactions with appropriate temporal and spatial resolution. Here we demonstrate picosecond grazing-incidence small-angle x-ray scattering (GISAXS) from laser-produced plasmas using XFEL pulses. Using multi-layer (ML) samples, both the surface ablation and subsurface density dynamics are measured with nanometer depth resolution. Our experimental data challenges the state-of-the-art modeling of matter under extreme conditions and opens new perspectives for laser material processing and high-energy-density science.
