Generation, amplification and nonlinear self-compression of powerful microwave Superradiance pulses

Superradiance (SR) of electron bunches can be considered as an effective method of production of ultrashort electromagnetic (em) pulses [1]. Different types of SR associated with different mechanisms (cyclotron, Cherenkov, bremsstrahlung) of stimulated emission have been observed experimentally in the millimeter and centimeter wavelength bands. Progress in this research has enabled a new type of generator to be created capable of generating unique short (under 200-300 ps) em pulses at super high peak powers exceeding 1 GW in the millimeter and 3 GW in the centimeter waveband. Some new methods for further increasing of the SR pulse peak power alongside with the promotion of such sources to higher frequency bands are discussed. These new methods include phase synchronization of several SR pulse generators [2], the amplification of an SR pulse during its propagation along a quasi-stationary electron beam [3] and nonlinear compression in the process of induced self-transparency [4].