Wang Zhao-Qi, Tang Jun, Hou Yong, Chen Qi-Feng, Chen Xiang-Rong, Dai Jia-Yu, Meng Xu-Jun, Gu Yun-Jun, Liu Lei, Li Guo-Jun, Lan Yang-Shun, Li Zhi-Guo
College of Physics, Sichuan University, Chengdu 610065, People's Republic of China.
National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900, People's Republic of China.
Phys Rev E. 2020 Feb;101(2-1):023302. doi: 10.1103/PhysRevE.101.023302.
The effective one-component plasma (EOCP) model has provided an efficient approach to obtaining many important thermophysical parameters of hot dense matter [J. Clérouin, et al., Phys. Rev. Lett. 116, 115003 (2016)PRLTAO0031-900710.1103/PhysRevLett.116.115003]. In this paper, we perform extensive quantum molecular dynamics (QMD) simulations to determine the equations of state, ionic structures, and ionic transport properties of neon and krypton within the warm dense matter (WDM) regime where the density (ρ) is up to 12 g/cm^{3} and the temperature (T) is up to 100 kK. The simulated data are then used as a benchmark to explicitly evaluate the EOCP and Yukawa models. It is found that, within present ρ-T regime, the EOCP model can excellently reproduce the diffusion and viscosity coefficients of neon and krypton due to the fact that this model defines a system which nearly reproduces the actual physical states of WDM. Therefore, the EOCP model may be a promising alternative approach to reasonably predicting the transport behaviors of matter in WDM regime at lower QMD computational cost. The evaluation of Yukawa model shows that the consideration of the energy level broadening effect in the average atom model is necessary. Finally, with the help of EOCP model, the Stokes-Einstein relationships about neon and krypton are discussed, and fruitful plasma parameters as well as a practical ρ-T-dependent formula of the effective coupling parameter are obtained. These results not only provide valuable information for future theoretical and experimental studies on dense neon and krypton but also reveal the applicability of the EOCP model and the limitation of the Yukawa model in WDM regime and further support the continuing search for a unified description of ionic transport in dense plasma.
有效单组分等离子体(EOCP)模型为获取热致密物质的许多重要热物理参数提供了一种有效方法[J. 克莱鲁安等人,《物理评论快报》116, 115003 (2016)PRLTAO0031 - 900710.1103/PhysRevLett.116.115003]。在本文中,我们进行了广泛的量子分子动力学(QMD)模拟,以确定密度(ρ)高达12 g/cm³且温度(T)高达100 kK的温稠密物质(WDM)区域内氖和氪的状态方程、离子结构及离子输运性质。然后将模拟数据用作基准,以明确评估EOCP模型和 Yukawa 模型。结果发现,在当前的ρ - T区域内,EOCP模型能够出色地再现氖和氪的扩散系数及黏度系数,原因是该模型定义的系统几乎能再现WDM的实际物理状态。因此,EOCP模型可能是一种有前景的替代方法,可在较低的QMD计算成本下合理预测WDM区域内物质的输运行为。对 Yukawa 模型的评估表明,在平均原子模型中考虑能级展宽效应是必要的。最后,借助EOCP模型,讨论了关于氖和氪的斯托克斯 - 爱因斯坦关系,并获得了丰富的等离子体参数以及有效耦合参数的实用ρ - T相关公式。这些结果不仅为未来关于稠密氖和氪的理论和实验研究提供了有价值的信息,还揭示了EOCP模型在WDM区域的适用性以及 Yukawa 模型的局限性,并进一步支持继续寻找对稠密等离子体中离子输运的统一描述。