高温高压液氢离解效应研究

Dissociation of Fluid Hydrogen at High Pressure and Temperature

在ab-initio理论基础上,利用前期获得的与实验吻合较好的CEIMC法模拟结果,采取配位数分析法详细研究了高温高压液氢的离解过程,确定了不同状态下液氢的离解度数值,系统讨论了分子离解对液氘冲击特性的影响.当冲击压力低于20 GPa时,液氘分子主要为双原子分子态;冲击压力大于53 GPa时,主要为单原子分子态;压力处于两者之间时为D2与D的共存态.在T-p面及T-P面内划分出了液氢分子开始离解及完全离解的临界线,认为高温高压液氢金属化应至少有50%氢分子离解.

Studying the dissociation of liquid hydrogen at extreme high pressure and temperature is very helpful for understanding its equation of state and thermodynamic properties.Based the previous ab-initio simulation results which were in good agreement with various experiments,the values of dissociation degree of hot dense hydrogen at different state points were calculated via the coordination number,and then the effects of dissociation in shocked deuterium on its thermodynamic properties were discussed.The results show that the deuterium is mostly a diatomic fluid blow 20 GPa,and almost a monatomic fluid above 53 GPa,with a dissociation of11.5%and 90%respectively,and thus a fluid composed of D2 and D between 20 GPa and53 GPa.Furthermore,two critical lines of liquid hydrogen in the T-ρ and T-P space when its dissociation nearly occurs or ends were mapped,and a suggestion that there is at least 50%dissociation at the onset of metallization in the dense liquid hydrogen was made.