Controlled Excitation and Dispersion Relations of Nonlinear Multimode Waves in Ion-Beam-Plasma System

Abstract

Controlled excitation of nonlinear multimode waves, including slow and fast ion-beam modes as well as an ion-acoustic mode, has been realized in a linearly stable ion-beam-plasma system. The mechanism for the coexcitation of two unlike waves observed in the system is also clarified. Furthermore, nonlinear dispersion relations of the beam modes are experimentally determined from the amplitude dependences of the wave velocities and widths. The results are compared with the theoretical ones.