Fund Project:Project supported by the Science and the Technology Foundation of State Key Laboratory of Shock Wave and Detonation Physics, China (Grant Nos. 6142A03192007, 6142A032020013) and the National Natural Science Foundation of China (Grant No. 11772311)
Received Date:04 March 2021
Accepted Date:20 April 2021
Available Online:07 June 2021
Published Online:05 September 2021
Abstract:Based on the electromagnetic loading device CQ-4, an experimental method of simultaneously measuring the refractive index and high pressure sound velocity of transparent material is established. The ramp wave compression experiment of PMMA is carried out under a pressure of 14 GPa. The velocity history curves of PMMA sample rear surface are obtained by dual laser heterodyne velocimetry (DLHV). The velocity curve shows obvious double wave structure, which indicates the elastic-plastic transition. The refractive index particle velocity optical characteristics and Lagrangian sound velocity particle velocity dynamic characteristics of PMMA are obtained simultaneously with the experimental data processing. Keywords:polymethyl methacrylate/ refractive index/ lagrange sound speed/ ramp wave loading
全文HTML
--> --> --> -->
2.1.磁驱动斜波压缩实验
斜波压缩实验在中国工程物理研究院流体物理研究所的磁驱动加载装置CQ-4[18]上开展. CQ-4装置由储能、开关和传输三部分组成, 加载电流上升沿约600 ns, 电流峰值可达4 MA. 磁驱动加载实验加载原理见图1所示, 具体见文献[1], 种涛等[19]指出斜波压缩实验的加载均匀性优于1%, 罗斌强等[20]分析了磁驱动斜波加载实验的不确定度, 结合理论分析和实验证明了磁驱动斜波加载是一种可靠的精密物理实验技术. 实验采用激光波长1550 nm的DLHV[21]开展速度测试, DLHV利用上、下变频两种工作模式对速度信号频率进行变换, 使得其在100 m/s以内低速段和10 km/s以上的高速段测量同时具有高的时间分辨率和测量精度. 图 1 磁驱动加载原理及样品布局 Figure1. Schematic diagram of magnetically driven ramp wave loading and layout of the samples.