Modelling of particle beams

The two-dimensional relativistic electromagnetic current-line code “POISSON 2” was used for numerical modelling of the behaviour of a relativistic electron beam (REB) in external and internal electromagnetic fields under various boundary conditions. The calculations confirmed that the generated beam is homogeneous and monoenergetic in a broad central region. In the case of cylindrical diode the mixing of electron trajectories was only observed in a narrow peripheral beam region. The formation of a virtual cathode (VC) by the REB propagating through the terminating foil into a vacuum region was also investigated. The dependencies of reflection coefficient of scattered beam by created VC on total beam current, beam energy, external magnetic field and on the length of vacuum drift tube were determined. Such data might be useful for additional plasma heating generated via a two-stream instability in our experimental REBEX devices.