太帕压力下声速连续测量的高精度靶制备

High Precision Targets Fabrication for Sound Velocity Measurements in Terapascal Pressure

声速反映小应力扰动在介质中的传播特征,是材料在一定热力学状态下的重要属性,是研究材料状态方程、相变(包括固-固相变)以及物质构成等的重要手段。超高压声速测量对于地球和行星物理、惯性约束聚变以及第一性原理的建模等多个物理研究领域具有重要意义。基于侧向稀疏方法连续测量冲击绝热线上的体声速是获取超高压声速的全新方法。该方法对靶的制备要求很高。为此,详细介绍了基于该方法的靶的制备要求,探讨了制备工艺、测量技术以及影响实验精度的主要因素,并根据"神光Ⅲ"原型装置的实验结果进行相应的分析。

Sound velocity is an intrinsic property of material,which is equal to the spread velocity of weak perturbation.Measurements of sound velocity are very important for the research of equation of state,phase transition and component of matter at extreme conditions.A continuous side-release method which can work to terapascal pressure was newly developed.In this paper,we described details of high precision targets fabrication of this method,including requirements,methodology and detection.Also,key factors which lead to fatal issues are analyzed for better signals and reliability.Experimental results on SGIII prototype laser facility are shown to validate the technology of targets fabrication.