Plasma Turbulence Generated by Ion-Ion Two-Stream instability

An instability is generated by injecting a high density ion-beam with a large cross-section into an unmagnetized homogeneous plasma. The linear dispersion relation of the wave in the ion-ion two-stream system is experimentally confirmed. Three-dimensional investigations of the turbulence thus produced reveal some new features: The turbulent waves propagate at large angles to the beam with extremely short correlation lengths. At these angles a rapid relaxation of the velocity distribution of the ions is observed until the beam temperature reaches around 0.2 T e . the observed rapid heating of ions can be explained by a theory incorporating the effect of orbit modification.