Abstract

Parametric instabilities of circularly polarized Alfvén waves propagating along a background magnetic field are investigated by means of a fluid/kinetic approach and particle simulations. It is found that, in addition to the collisionless effects on the decay instability as described by a driftkinetic treatment [Inhester, B., J. Geophys. Res. 95, 10525 (1990)], ion kinetics leads to instabilities that are absent in the fluid description. A brief comparison of our theoretical results with computer simulations is presented.