金刚石对顶砧（DAC）与X射线衍射（XRD）结合，是研究物质结构相变的有效途径，但目前主要限于平衡态的测量，不能研究相变的动力学过程。在很多情况下，材料的相变行为与压力的加载速率有关，因此发展相应的技术，开展时间依赖的相变研究，是高压科学提出的新的技术挑战。本项目旨在DAC静态压缩技术的基础上发展压力快速加载技术，以及压力快速变化下的晶体结构测量技术。在此基础上，对典型相变材料的相变动力学特性进行实验研究。项目研究首先完成一套快速加载DAC装置的研制，获得 >2000 GPa/s的加载速率。利用同步辐射光源和先进的探测器，发展适于快速加载条件的时间分辨衍射技术，在DAC中实现样品在压力快速变化下的原位测量。对Bi、Sn等典型相变材料进行原位的快速加载衍射研究，测量材料在不同加载速率下的结构变化，获得相变动力学行为的规律性认识。

Diamond anvil cell and x-ray diffraction techniques are essential to study the phase transitions of materials under extreme conditions. Until now, it mainly focuses on the equilibrium states. The dynamic process of the phase transitions is currently unexplored for most phase transformation. In many cases, the phase transformations for materials are compression-rate dependent. Therefore, it is a new challenge in the high-pressure field to develop dynamic compression equipment and perform in situ time-resolved measurements. The purpose of this project is to develop rapid compression apparatus and x-ray diffraction technique for the measurements under rapid compression. Based on these, we will investigate the dynamic process of the phase transition in some classical materials. In this project, we will first design and complete a rapid compression apparatus for dynamicbased on diamond anvil cell, and obtain compression rate of 2000 GPa/s. By using this apparatus, we will perform in situ x-ray diffraction measurements of the phase transitions under rapid compression in synchrotron source, and observe the compression-rate dependence of structural change. This will provide new insight into understanding the behavior of the dynamic phase transitions.