Four-dimensional (spatial and temporal) investigation of hard x-ray emission produced by intense femtosecond laser interactions with solid targets

提出了一个研究计划，旨在解决一些重要的，但知之甚少的问题，在硬X射线发射短脉冲，高强度激光与固体靶相互作用。特别注意的是快速电子传输的作用和周围的目标材料，这在很大程度上决定了空间和时间源特性的K？和韧致辐射的X射线发射。为此目的，最近开发的三维，无网格模型将被使用，这是能够处理激光与几何复杂的目标与有限的电阻率，这是目前超出了传统的动力学模拟工具的任务的相互作用。这一理论研究将与专门设计用于通过K发射测量探测异常传输行为的实验一起进行。如果成功，该项目将导致更好的物理理解飞秒x射线产生在高激光强度，并提供迫切需要的指导，以提高K源效率。因此，这项研究的结果将对Schwerpunktprogramm中的许多其他项目产生直接影响，这些项目依赖于衍射和光谱应用中的高Ka光子通量。

A research program is proposed aimed at resolving a number of important but poorly understood issues in hard x-ray emission from short-pulse, high-intensity laser interactions with solid targets. Particular attention will be given to the role of fast electron transport in and around the target material, which largely determines the spatial and temporal source characteristics of both K¿ and bremsstrahlung x-ray emission. For this purpose, a recently developed three-dimensional, mesh-free model will be used which is capable of handling laser interactions with geometrically complex targets with finite resistivity, a task which is currently beyond the reach of conventional kinetic simulation tools. This theoretical investigation will be performed in tandem with experiments specifically designed to probe anomalous transport behaviour via K¿ emission measurements. If successful, the project will lead to better physical understanding of femtosecond x-ray generation at high laser intensities and provide urgently needed guidance for increasing K¿ source efficiency. As such, the results of this study will have a direct impact on many of the other projects within the Schwerpunktprogramm which depend on high Ka photon flux for diffractometry and spectroscopy applications.