Cherenkov maser based on a twodimensional periodic lattice

We present the results of study of a Cherenkov maser based on a 2D periodic lattice used to achieve the desired level of output power while still maintaining the coherence of the output radiation. In this case the large interaction region formed by the periodic lattice allows a moderate power density inside the beam-wave interaction space whilst simultaneously avoiding the formation of electron beam instabilities associated with high beam charge density. We demonstrate that the structure also provides effective mode selection over the azimuthal and radial wave numbers. The results of the studies of the operation of a Cherenkov maser based on a 2D periodic lattice are presented and we show that a single mode, steady state operation at a frequency of ~90GHz was achieved. The conditions required to observe effective interaction between the electron beam and an EM wave are also discussed.