Thermodynamic Characteristics of Dusty Plasma Studied by Using Molecular Dynamics Simulation
Thermodynamic Characteristics of Dusty Plasma Studied by Using Molecular Dynamics Simulation
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DOI：
10.1088/1009-0630/14/9/01
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发表时间：
2012-02
影响因子：
1.7
通讯作者：
A. Shahzad;M. He 何
中科院分区：
文献类型：
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作者：
A. Shahzad;M. He 何
在正则系综下用分子动力学模拟方法研究了德拜-汤川粒子系统的热力学性质。用两种不同的方法计算了德拜-汤川体系的超额自由能f，得到了耦合参数为0≤Γ≤10 0和较大屏蔽参数κ范围内的超额自由能f。文中还给出了系统超量纲参数(κ，Γ)的超内能和超压的模拟测量结果，并与以前的理论和模拟结果进行了比较。介绍了一种Γ展开拟合法，其中的展开系数是筛选参数κ的函数。拟合系数直接与模拟值进行比较，相对偏差小于或等于1%。计算结果表明，在某些对Γ有很强依赖性的情况下，计算结果提供了一种相对简单的方法来计算超额内能和自由能。
Thermodynamic properties of a Debye-Yukawa system of particles are explored by using molecular dynamics simulation in the canonical ensemble. The excess free energy f of the Debye-Yukawa system is calculated by using two different approaches for the liquid phase, and the energy is obtained in a coupling parameter range of 0 ≤ Γ ≤ 100 and a wide range of the screening parameter κ. Simulation measurements for excess internal energy and pressure of the system over dimensionless parameters (κ, Γ) are also presented and compared with previous theoretical and simulated results. A Γ-expansion-fitting approach for the liquid phase is introduced with the expansion coefficients, which are functions of the screening parameter κ. The fitting coefficients are obtained by directly comparing them with the simulation measurements with a relative deviation of 1% or less. It is shown that the computational results provide a relatively simple method to calculate the excess internal energy and free energy in certain cases, which depend strongly on Γ.