Dynamic stabilization of the two-stream instability during longitudinal compression of intense charged particle beam propagation through background plasma

The electrostatic two-stream instability for a cold, longitudinally-compressing intense ion beam propagating through a background plasma has been investigated both analytically and numerically. The linear development of the instability and its saturation are examined from the point of view of wave dynamics, where the plasma waves are represented as quasi-particles characterized by their position x(t)x(t), wavenumber k(t)k(t) and energy (or frequency) ω(t)ω(t). It is found that the longitudinal beam compression strongly modifies the space-time development of the instability. In particular, the dynamic compression leads to a significant reduction in the growth rate of the two-stream instability compared to the case without an initial velocity tilt.