Diffusion Coefficient of Weakly Coupled Plasmas Under Biaxial Electric Field

Diffusion processes may occur during plasma-surface interactions in fusion devices and can display spontaneous transport behavior when subjected to an external electric field. Given the gaseous characteristics of the weakly coupled (WC) plasma system, we investigated how constant-level of normalized biaxial electric field (E*) influences order–disorder structures, confirming that the plasma system persists in a disordered (gas-like) state. We have performed molecular dynamics (MD) simulations to determine the diffusion coefficient in three-dimensional WC plasmas under the influence of varying E*. The calculations of the diffusion coefficient, with suitable normalizations, are estimated across a wide range of plasma states (Γ, κ) in the limit of low and extended range of biaxial E* strengths. It has been demonstrated that a strong correlation exists between the diffusion coefficient and plasma states, which corroborates the existence of highest diffusion coefficient values. The presence of these peak values is elucidated by the maximum kinetic contribution to the diffusion coefficient in the WC regime. Moreover, an observed trend indicates that the diffusion coefficient increases as E* rises. Conversely, the diffusion coefficient diminishes with an increase in Γ, while it experiences an increase when there is a rise in the system's screening κ. The computed diffusion coefficients have shown a satisfactory alignment with parts of earlier MD results, with the most of current values typically overestimating the diffusion coefficient by 3%–30%, contingent upon plasma states. The simulation data for low value biaxial E* have been observed to conform to the universal temperature scaling law. These insights enhance our understanding of the behavior of dust particles and have important applications in inertial confinement fusion devices and astrophysical environments.