Transition radiation in a waveguide with semi-bounded cold plasma

We analyze transition radiation of a charge crossing the boundary between vacuum and cold plasma in a waveguide. We obtain exact and approximate expressions with the steepest descend technique for the field components. It is shown that the electromagnetic field has the different structure in vacuum and cold plasma. We develop an algorithm for computation of the field based on a certain transformation of the integration path. Behavior of the field components depending on distance and time is explored for different velocities of the charge motion. Some important physical effects are noted. So, considerable increase and concentration of the field near the “wave front” in plasma is observed for the case of ultra-relativistic particle. As well, in plasma the envelope of the field has the zero point if the charge velocity is within certain limits.