Abstract View
Thermodynamic Equations of State for the Dust Grain Using Langevin Dynamics Simulations
VIKRAM SURESH, Zhibo Liu, Ranganathan Gopalakrishnan, The University of Memphis
Abstract Number: 188
Working Group: Dusty Plasma
Abstract
The complex plasma is modeled as an isotropic system of N charged grains (radius ap and charge Zp) interacting with each other through a screened Coulomb potential with a fixed Debye length λD in an isotropic periodic domain, without including a confining potential and the systematic drift of charged species. The equilibrium thermodynamic state is investigated using Langevin Dynamics simulations to capture the effect of grain-neutral gas interactions (parameterized by the grain Knudsen number Kn≡λg/ap) across the various Γ ≡ (Zp2e2/(4πεonp-1/3kbTd)), κ=np-1/3/λD -based electrostatic coupling regimes, where np is number concentration and Td is the kinetic temperature of the grains. The Langevin-computed internal energy ud, pressure pd and kbTd of the grain phase are parameterized as equations of state f(ud,pd,kbTd) and compared with experimental reports of dust kinetic temperature to refine the modeling assumptions. The non-trivial influence of grain-neutral gas interactions is discussed by calculating the pair correlation functions in the gas, liquid, and solid-like regimes of grain correlated behavior. A unified thermodynamic model will further the understanding of phase transitions and the transport properties of the dust phase across the entire Γ, κ, Kn regimes.
We thank The University of Memphis High Performance Computing Cluster for providing computational resources to carry out this research. Funding for this work was provided by DOE Office of Fusion Energy Sciences Award DE-SC0021146