Ion heating via turbulent ion acoustic waves.

The ion acoustic turbulence in the turbulent-heating experiment reported is excited by the ion-ion beam instability. Graphs are presented, showing the spatial evolution of the parallel ion beam energy and the spatial evolution of the ion acoustic turbulent wave spectrum. The observed characteristics of test waves in a turbulent beam-plasma imply that wave saturation is a dynamic balance between the emission of waves by the beam and the destruction or damping of wave coherence by the turbulent diffusion of particle orbits.