The physical mechanism of the Alfvén ion-cyclotron instability due to ion-temperature anisotropy in a high-$\beta$ plasma is explored. We have observed evidence for the proposed mechanism in runs on a magnetostatic particle simulation code. Saturation and stabilization of the instability are discussed on the basis of the present mechanism.

• Received 5 April 1977

DOI:https://doi.org/10.1103/PhysRevLett.39.201