Gyrokinetic applications in electron-positron and non-neutral plasmas

In this paper, we summarize our recent work on gyrokinetic applications in electron-positron and non-neutral plasma. The electrostatic stability of electron-positron plasmas was investigated in dipole and slab geometries, with and without ion admixture. The gyrokinetic dispersion relation was derived and, for the slab case, extended to non-neutral plasmas. Here, we further extend the gyrokinetic formulation to the relativistic regime. Electron-positron plasmas are found to be remarkably stable as long as perfect symmetry between the two species prevails, but instabilities appear if this symmetry is broken, for instance by the introduction of impurities or magnetic curvature.