Anisotropic-ion-beam-plasma interaction: drift perpendicular to magnetic field

Using kinetic theory, low-frequency electrostatic instabilities driven by an anisotropic ion beam are investigated. In the model both the ions and electrons are magnetized, while the beam drift is across the external magnetic field. Both the ion-acoustic and ion-ion two-stream instabilities are excited. Regions of parameter space for the existence of either instability are distinguished. Detailed comparisons are made with the isotropic case. (author)