The interaction of electromagnetic wave and plasma wave in an electron beam-ion channel system

The features of the waves and the instability induced by the interaction of electromagnetic (EM) wave with plasma wave in the electron beam-ion channel system are studied. Characteristics of waves in the system are displayed through the dispersion relation and two kinds of EM instabilities are found. The first one is excited by the interaction of the fast plasma wave and the forward EM wave, and the other one is induced by the coupling of the fast plasma wave and the backward EM wave, the numerical results show that this is caused by the virtual cathode oscillation. The conditions of these EM instabilities are given and the related physical mechanisms have been discussed in detail.