Nonlinear Development of the Beam-Cyclotron Instability

Abstract

A theory is presented for the nonlinear evolution of the beam-cyclotron instability, together with the results of a series of computer experiments confirming the main points of the theory. We conclude that at a turbulent level which is proportional to ${(\frac{{\ensuremath{\Omega}}_{\mathrm{ce}}}{{\ensuremath{\omega}}_{\mathrm{pe}}})}^{2}$, a transition is made to the nonmagnetic ion acoustic instability. For small $\frac{{T}_{i}}{{T}_{e}}$, the system then evolves until the fluctuating fields become strong enough to stabilize by ion trapping.