Plasma Instabilities in Linear and Quasi-Linear Regime

Abstract

Kinetic Plasma instabilities are important for regulating the temperature anisotropies of electrons and ions in the solar wind. The plasma compression generates the perpendicular anisotropy, T┴ >Tll, which leads the mirror instability for high beta situation but for low beta regime the electromagnetic ion/electron cyclotron (EMIC/EMEC) instabilities. The said unstable modes including electrons are simplified and reduced quasi linear kinetic theory with assumption of bi-Maxwellian velocity distribution function. For mirror mode instability, the linear growth rate of electron mirror mode can be much higher than the proton mirror mode and electron part operates over a range of unstable wave numbers that is much broader than proton part. But in quasi linear analysis, high initial growth rate does not necessarily imply dynamical importance, the saturated magnetic field intensity associated with electrons is extremely low and that the influence on the particle temperature is minimal. The EMIC/EMEC instabilities are taken into account with parallel propagation in two dimensions. The present manuscript extends the analysis to two (or with cylindrical symmetry, three) dimensions. The analysis is further extended to include quasilinear description with the assumption of bi-Maxwellian velocity distribution function. Such an analysis lays the foundation for eventual study in which cyclotron instabilities as well as obliquely propagating unstable modes such as the mirror instability are simultaneously taken into account.