MAGY - A TIME-DEPENDENT CODE FOR SIMULATION OF SLOW AND FAST MICROWAVE SOURCES

We present the newly developed Maryland Gyrotron (MAGY) code for model ing of slow and fast microwave sources. The code includes a time-depen dent description of the electromagnetic fields and a self-consistent a nalysis of the electrons. The calculations of the electromagnetic fiel ds are based on the waveguide modal representation, which allows the s olution of a relatively small number of coupled one-dimensional partia l differential equations for the amplitudes of the modes, instead of t he full solution of Maxwell's equations. Moreover, the basic time scal e for updating the electromagnetic fields is the cavity fill time and not the high frequency of the fields. The equations of motion of the e lectrons are formulated within the framework of the guiding-center app roximation and solved with the electromagnetic fields as the driving f orces. Therefore, at each time step, a set of trajectories are calcula ted and used as current sources for the fields. We present two example s for the operation of the code, namely the two-cavity gyroklystron an d the backward-wave oscillator (BWO), These examples demonstrate the p ossible usage of the code for a wide variety of electron-beam systems.