Spontaneous pulse width limitation in S-band two-sectional vircator

The paper presents a review of continuing studies on production of S-band microwave pulses in a two-sectional single-mode vircator [1, 2] based on long-pulse (sub-microsecond) high-voltage generators. The two pulsers were used (a) generator with inductive energy store and fuse opening switch and (b) generator based on Marx bank and water forming line. The peak microwave output was on the range of ~1 GW. Substantial spontaneous shortening of the microwave pulse was observed (50-100 ns). Possible mechanisms for this phenomenon are discussed and supported by 3-D KARAT simulations.