Preferential acceleration of heavy ions in multi-component plasmas

Abstract

We discuss preferential, perpendicular acceleration of α particles in large amplitude magnetohydrodynamic (MHD) waves by using a test particle simulation. In a 3 component plasma that consists of electrons, protons and α particles, one of the wave branches has phase velocity larger than the Alfvén velocity in a long wave length regime. We find that the wave-particle interaction between this wave and the other Alfvén wave leads to strong anisotropic acceleration in perpendicular direction to the ambient magnetic field. We examine the wave-particle interaction for a 3 component plasma, and obtain good agreement with the test particle simulation.