High current electron beams for high power FEM based on 2D periodic lattices

In this paper, we report the observation of high-current (1.5 kA), magnetically confined, annular electron beams with circumference of -220 mm and wall thickness of ~2 mm and its transportation through the 2 m coaxial beam channel with inner/outer radii of 30 mm/40 mm respectively. The results of the experimental studies of a FEM driven by such an electron beam are presented. The results of FEM lasing using the beam are demonstrated. We also present a comparison between the experimental data and theoretical predictions obtained using the PiC codes KARAT and MAGIC.