Resonant wave-particle interactions modified by intrinsic Alfvénic turbulence

Abstract

The concept of wave-particle interactions via resonance is well discussed in plasma physics. This paper shows that intrinsic Alfvén waves can qualitatively modify the physics discussed in conventional linear plasma kinetic theories. It turns out that preexisting Alfvén waves can affect particle motion along the ambient magnetic field and, moreover, the ensuing force field is periodic in time. As a result, the meaning of the usual Landau and cyclotron resonance conditions becomes questionable. It turns out that this effect leads us to find a new electromagnetic instability. In such a process intrinsic Alfvén waves not only modify the unperturbed distribution function but also result in a different type of cyclotron resonance which is affected by the level of turbulence. This instability might enable us to better our understanding of the observed radio emission processes in the solar atmosphere.