Diffusion coefficients of dusty plasmas in electric field

Abstract

In this work, the effects of normalized electric field (E^*) on parallel diffusion coefficients (D_||) and perpendicular diffusion coefficients (D_┴) are investigated through equilibrium molecular dynamics (EMD) simulations in three-dimensional strongly coupled dusty plasmas. The self-diffusion coefficients (D_E) for three dimensions also have been calculated for the wide range of plasma Coulomb coupling (Γ) and Debye screening (κ) parameters with the various system sizes. The D_E, D_|| and D_┴ are investigated using the Einstein relation with EMD simulations. The effects of constant and varying normalized E^* on D_|| and D_┴ have been computed for the different system sizes. Simulation outcomes are outstanding in the combined effects of E^* and κ and give well-matched D_E, D_||(E^* = 0, 0.01) and D_┴(E^* = 0, 0.01) values at low-intermediate to large Γ with varying small-intermediate to large N. The D_|| and D_┴ in the limit of varying E^* values are accounted for an appropriate range Γ and κ parameters. At varying E^* values, it is revealed that the D_|| increases and D_┴ decreases with an increase in E^*; however, it decreases with an increase in Γ but within statistical limits. The simple analytical temperature scaling law is tested for variation of scaled (Einstein frequency) D_E, D_||(E^* = 0.01) and D_┴(E^* = 0.01). It has been shown that the present EMD simulations data obtained for the appropriate range of E^* strength up to 0.01 ≤ E^* ≤ 1.0 to understand the phase transitions, fundamental nature of E^* linearity and anisotropy of dusty plasma systems.

Graphical abstract

Diffusion coefficients of dusty plasmas in electric field by using molecular dynamics simulation.