Operation of high-power planar Fem with two-dimensional Bragg reflectors (theoretical and experimental investigations)

Recent results of investigations on powerful 4-mm planar FEM driven by sheet electron beam in case of 2-D distributed feedback are described. Spectral properties of Bragg resonators and generated power together with its dependency on undulator field are measured for the various resonators. Obtained dependencies are in agreement with ones predicted by theoretical models. Power level and pulse duration are limited by microwave shortening in the experiments. Prospects of increasing of these parameters are discussed.