高压条件下材料强度测量方法北大核心CSCD

在神光Ⅲ原型激光装置上开展了Al材料在高压（大于10GPa）、高应变率（10^5～10^8s^-1）的情况下材料强度特性实验方法研究。实验采用“有机材料真空间隙一样品”的靶构型（气库靶）对Al样品进行准等熵压缩，从而使Al样品的温度保持在熔点以下，材料仍具有强度特性。为了测量Al样品的RT不稳定性扰动增长，实验采用Ti作面背光材料，通过X光针孔成像获得样品的面向背光照相图像，获得了不同时刻RT不稳定性的增长因子，实验中采用连续相位板（CPP）对激光源进行了优化，提高了背光源和驱动源的均匀性。结果表明在现有高功率激光装置上可进行中z材料的RT不稳定性增长测量，验证了通过RT不稳定性增长测量来研究高压高应变率条件下材料强度的可行性。

Measurement of material strength at high pressure

We studied material strength at high pressure ( more than 10 GPa) and high strain rates (106-108 s-1) in Al using the Shenguang Ⅲ prototype laser facility. The Al sample was maintained well below the melting temperature using a quasi-isentropic ramped drive based on a reservoir-gap-sample configuration. To measure the RT ripple growth, we used face-on radiography with a 4.7 keV laser driven Ti X-ray backlighter. This paper would show detailed designs and achieve the RT growth factors at different times. In the experiment, continuous phase plates (CPP) were used to improve the focus beam quality. The results show that CPP can effectively improve the uniformity of driven beam and the backlighter beam. Finally the experimental results reveal that the method to infer material strength by measuring RT instability growth is feasible at Shenguang Ⅲ prototype laser facility.