MAGY: a self-consistent code for modelling electron beam devices

Summary form only given, as follows. MAGY is a quasi three dimensional self consistent time dependent code for modeling of electron beam systems. We assume that the system consists of a cylindrically symmetric waveguide with an arbitrarily varying wall radius (including jump discontinuities) and represent the electromagnetic fields as a set of transverse electric and transverse magnetic modes which are defined by the local value of the wall radius. We thus obtain a set of coupled transmission line equations for the voltage and current amplitudes of the various modes. The coupling of the modes originates in the variations of the wall radius, finite conductivity of the walls and the electron beam. We describe the electron dynamics using the guiding center formulation of the equations of motion with an arbitrary profile of the guiding magnetic field. A significant simplification of these equations is obtained when all the particles traverse the cavity in a time shorter than the cavity fill time. The combined set of equations for the electromagnetic amplitudes and the electron trajectories form the reduced description we are employing in the MAGY code. In the work we present first results obtained with the new MAGY code for generic Gyrodevices and a Backward Wave Oscillator.