Zhang X P, Gu Z W, Xiao Z Q, Tan F L, Ye X Q, Tong Y J, Tang X S, Zhou Z Y, Cheng C, Zhao J, Luo B Q, Li J M, Kuang X W, Zhao J H, Sun C W, Liu C L
Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China.
Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621907, China.
Rev Sci Instrum. 2022 Apr 1;93(4):043906. doi: 10.1063/5.0078422.
The knowledge of high-pressure behavior of LiH is significant for the validation of fundamental theoretical models and applications in thermonuclear materials and potential energy supplies. The compressibility of LiH under isentropic compression at high pressure was investigated experimentally and theoretically. The experimental technique for quasi-isentropic compression with low-density materials was developed using the magnetocumulative generator CJ-100 and x-ray flash radiography. The x-ray images and extracted interface of the sample target in dynamic flash radiography experiments were obtained. According to each interface size of the target both before and after compression, the compression ratio of LiH and reference material aluminum was obtained. The density of the reference and using its known isentropic curve provide the pressure in the reference. The pressure in LiH was deduced from the pressure in the reference and using the calculated gradient correction factor. The quasi-isentropic data point at 438 GPa was obtained experimentally. A semiempirical three-term complete equation of state was constructed and validated for LiH using the theory of Mie-Grüneisen-Debye with experimental data from the literature. The quasi-isentrope data point is reasonably consistent with the theoretical results. The quasi-isentropic experimental techniques and results broaden the existing research scope and are practical and helpful to further validate theoretical models in the future.
氢化锂高压行为的知识对于基本理论模型的验证以及在热核材料和潜在能源供应中的应用具有重要意义。对氢化锂在高压等熵压缩下的压缩性进行了实验和理论研究。利用磁累积发生器CJ - 100和X射线闪光射线照相技术，开发了低密度材料的准等熵压缩实验技术。在动态闪光射线照相实验中获得了样品靶的X射线图像和提取的界面。根据压缩前后靶的各界面尺寸，得到了氢化锂和参考材料铝的压缩比。参考材料的密度及其已知的等熵曲线提供了参考压力。氢化锂中的压力是根据参考压力并使用计算出的梯度校正因子推导出来的。在438 GPa下获得了准等熵数据点。利用米 - 格鲁涅森 - 德拜理论和文献中的实验数据，构建并验证了氢化锂的半经验三项完整状态方程。准等熵数据点与理论结果合理一致。准等熵实验技术和结果拓宽了现有研究范围，对未来进一步验证理论模型具有实际意义且有所帮助。
