摘要
液氢在较宽压力与温度范围内具有复杂的物理特性,须从分子层面构建精确模型开展探索研究。利用电子-核耦合的CEIMC法模拟液氘单次冲击实验,分析了液氘冲击特性,当压力达50.3GPa时液氘具有最大压缩率4.48,在110GPa冲击压力附近未发现有压缩率急剧增大的迹象。选用合适的Al基板材料模型,建立了液氘单次压缩状态与实验条件间的关系,总结了单次冲击实验规律。得到的状态方程与现有动高压实验结果一致,也与经修正后的100GPa以上压力的Omega激光实验值吻合,说明采用基于共振价键理论的波函数后,CEIMC法可应用于液氘的冲击模拟。
Since liquid hydrogen has some complex physical behaviors in a relatively wide range of pressure and temperature,one more accurate and appropriate ab-initio simulation method is urgently required.We used the Coupled Electron-Ion Monte Carlo(CEIMC)method to simulate the single shock compression experiment of deuterium,and systematically studied its thermodynamic properties under high pressure.It is shown that the liquid deuterium principle Hugoniot has a maximum compression ratio of 4.48 at about 50.3GPa,but the compression ratio does not increase gradually around 110 GPa.By utilizing an appropriate aluminum impedance match model,we have established the correlations between the states of compressed deuterium and the shock or particle velocities in aluminum taken before the shock wave crossing the Al-D2 interface,and contemporarily summarized the physical processes of liquid deuterium under single shock compression in detail.The calculation results are not only in very good agreement with the existing experiments via different high-pressure generating technologies,but also consistent with the data above 100 GPa corrected from the Omega Laser driven experiment.Therefore,the CEIMC method combined with the wave function based on the resonant valence bond theory is very suitable for the simulations of shocked liquid deuterium.
出处
《高压物理学报》
CAS
CSCD
北大核心
2015年第1期1-8,共8页
Chinese Journal of High Pressure Physics
