Chaotic operation of a delayed-feedback klystron oscillator: Theory and experiment

The dynamics of a delayed-feedback microwave self-excited oscillator built around a drift-tube klystron is studied theoretically and experimentally. I t is revealed by computer simulation that the operation of this oscillator must be undergoing an intricate sequence of bifurcations, with the bifurcat ion parameter being proportional to the beam current and the amount of feed back. The oscillator thus alternates between regular and chaotic modes of s elf-modulation. The transitions to chaos mostly proceed via a succession of period-doubling bifurcations. The operation of an experimental oscillator with a five-cavity amplifier klystron is tested. The experimental results a gree with the simulation data in qualitative terms.