Phase-locking of strongly coupled relativistic magnetrons

Phase-locking of two strongly coupled S-band relativistic magnetrons in the gigawatt regime was achieved. A single high-voltage pulser drives the two relativistic magnetrons connected by a short waveguide of length approximately=n lambda /2. Equal power flows in both directions between the magnetrons. The time required to lock is approximately=7 ns. Phase-locking lasts for approximately=15-20 ns. Phase-locking in the pi and 2 pi modes is demonstrated by direct phase measurement. The RMS peak power is approximately=1.6 GW in the pi -mode and 400 MW in the 2 pi -mode. Power density enhancement due to source coherence is directly measured in the radiation field. Locked phase measurements agree with phenomenological modeling of the experiment using a simple van Der Pol model.>