激光加载是实验室获得高温高压极端环境的重要技术手段之一，但其极短的加载时间使得我们无法使用常规的方法测量材料在该过程中的状态参数，因此发展适应于激光加载平台特点、在短时间尺度内得到物质状态参数的原位测量方法，将是系统研究极端环境物质状态的前提和必要条件。本项目申请拟发展基于X射线吸收谱扩展边精细结构（Extended X-ray Absorption Fine Structure, EXAFS）对激光加载过程中材料状态参数的原位测量技术，我们将通过引入可变力场参数分子动力学模拟，发展新型的EXAFS谱数据拟合分析方法，同时设计X射线光学系统，改进现有的EXAFS测量实验方案，通过理论和实验两方面的改进，我们期望克服现有EXAFS测量技术的局限和不足，建立对激光加载过程中固态材料温度、密度及相结构原位精确测量的能力，这将对极端条件下物体方程和加载动力学的研究具有积极的推动和促进作用。

As one of the most important techniques to obtain the high temperature and high pressure condition in laboratory, laser driven experiment is characterized as the extremely short loading time (10-9s), which prevents the utilization of conventional methods to measure the state parameters during the loading process, thus it's necessary to develop the new measurement scheme which can precisely and immediately gather the state parameters. In this project application we plan to develop the in-suit measurement technique in laser driven platform based on Extended X-ray Absorption Fine Structure (EXAFS): in the theoretical aspect, we will develop the new EXAFS data fitting and analysis methods by employing the force field changeable molecular dynamics, and in experimental aspect, we will design a X-ray optical system to improve the present EXAFS measurement scheme. Over the efforts both in theory and experiment, we plan to overcome the limits of the present EXAFS measurement technique and establish the ability to precisely obtain the information of temperature, density as well as phase structure in laser driven experiments. This project application can be expected to enhance the researches in the matter state equation and dynamic process of material under extreme conditions.