Particle aspect analysis of electromagnetic ion cyclotron instability

Abstract

The electromagnetic ion cyclotron instability, incorporating the details of charged particles trajectory, has been discussed. The wave is assumed to propagate along the ambient magnetic field in an anisotropic plasma. The plasma is considered to consist of resonant and non-resonant particles. Here it is assumed that resonant particles participate in energy exchange with the wave whereas the non-resonant particles support the oscillatory motion of the wave. Growth rate has been obtained by an energy conservation method for an arbitrary velocity distribution function. The effect of non-resonant particles on the resultant growth rate has also been discussed. The maximum growth rate has been evaluated for various values of β (ratio of kinetic pressure to magnetic pressure) and [Formula: see text]. The marginal stability criterion has also been derived. The time development of the ion cyclotron instability and the change in the resonant particles energy have been computed for magnetospheric plasma.