Collision induced amplification of wakes in streaming plasmas
Abstract
This work examines the formation of wake fields caused by ions streaming around a charged dust particle, using three-dimensional particle-in-cell (PIC) simulations with charge-neutral collisions included. The influence of an external driving electric field, which leads to a non-Maxwellian distribution of ions, is investigated in detail. The wake features formed for non-Maxwellian ions exhibit significant deviations from those observed within the model of a shifted Maxwellian distribution. The dependence of the peak amplitude and position of the wake potential upon the degree of collisionality is analyzed for a wide range of streaming velocities (Mach numbers). In contrast to a shifted Maxwellian distribution of ions, the drift-driven non-Maxwellian distribution exhibits an increase of the wake amplitude of the first attractive peak with increase in collisionality for high streaming velocities. At very low Mach numbers, collision-induced amplification is observed for Maxwellian as well as non-Maxwellian distributions.
Keywords
Cite
@article{arxiv.1702.07152,
title = {Collision induced amplification of wakes in streaming plasmas},
author = {Sita Sundar and Hanno Kählert and Jan-Philip Joost and Patrick Ludwig and Michael Bonitz},
journal= {arXiv preprint arXiv:1702.07152},
year = {2017}
}