On the effect of electron-mass variation in numerical simulations of the Farley-Buneman instability (Q1037151)

From the abstract: The Farley-Buneman plasma instability occurs in weakly ionized matter in the presence of a fairly intense electric field perpendicular to the magnetic field. It is excited when the electrons are magnetized while the ions are demagnetized owing to frequent collisions with neutral particles. Many simulations of such a type of instability used algorithms based on the particle method which has many shortcomings. In particular, the solutions obtained with this method involve numerical noises owing to a finite number of the particles, since the electron mass is increased in order to reduce the computational complexity of the algorithm. In this study, the effect of the increase in the electron mass on the qualitative and quantitative characteristics of the instability development are considered. For this purpose, a software package developed on the basis of a mathematical model consisting of the Poisson equation for the electric potential, the fluid equation for the electrons, and the kinetic equation for the ions is used. The equations are solved numerically, which makes it possible to avoid the problems inherent in the particle method. An important result obtained in this paper is that even a slight increase in the electron mass leads to a considerable variation of the instability development parameters. This variation manifests itself as an increase in the wavelength of plasma fluctuations and a decrease in the strength of the turbulent electric field.