用多次冲击压缩方法研究稠密氢氦等摩尔混合气体的物态方程

Investigation of the pressure-volume-temperature equation of state for dense hydrogen-helium mixture using multi-shock compression method

采用液氮冷却以及气体增压技术,制备了～30MPa及～90K初始状态的氢、氦等摩尔混合气体样品.以二级轻气炮作为加载工具,用不同灵敏度设置的两套多通道瞬态高温计系统获得完整、清晰的稠密氢、氦混合气体多次冲击压缩过程的光谱辐射强度信号.并建立起相应的实验数据处理和分析技术,获得了5—140GPa范围内氢、氦混合气体一至五次冲击雨贡纽物态方程,以及一次、二次和四次冲击温度实验数据.流体变分理论和离解模型用来分析和解释所获得的测量结果.

The multi-shock Hugoniot and shock temperatures of gaseous hydrogen-helium equimolar mixture with initial pressure and temperature of - 30MPa and - 90 K have been measured up to 140 GPa using two-stage light gas gun and shock reverberation technique. Two kinds of multi-channel pyrometer systems with different sensitivities, were used in experiment for diagnostics, because the thermal radiation of the sample in the first-shock state is lower than that in the multi-shocked states by a magnitude of one to two orders. The measured pressure, volume and temperature are respectively 5GPa, 12.0 cm^3/mol and 3030 K in the first-shock state, 27 GPa, 6.7 cm^3/mol and 5070 K in the second -shock state, and 105 GPa, 4.0 cm^3/mol and 5090 K in the fourth-shock state. The results for the first- and second-shock states are well described by the fluid perturbation theory and dissociation model. It demonstrates that the dissociation of molecular hydrogen of the compressed sample is negligible in the first- shock state, while about 7% and 32% of molecular hydrogen undergo dissociation in the second- and fourth -shock states, respectively. The fourth-shock temperature measured was lower than the prediction for - 2000 K.