Theoretical study on two beams interactions in cylindrical waveguide filled with plasma

The interaction of two electron beams in a cylindrical waveguide filled with plasma is studied in this paper. The linear theory is established based on a fluid model. The numerical results show the two-stream instability of two electron beams can produce Cherenkov radiation through the interaction between the fast space charge wave and the slow space charge wave, and the frequency of radiation can be above the plasma frequency. When the plasma frequency exceeds the frequency scope of the interaction, the interactions of beam-plasma and beam-beam can be improved and enhanced greatly.