Figure 6
From: A high-efficiency L-band coaxial three-period relativistic Cherenkov oscillator

Simulation results of the L-band coaxial three-period relativistic Cherenkov oscillator: (a) the PIC simulation model (1-circular cathode, 2-cut-off neck, 3-outer SWSs, 4-inner SWSs, 5-coaxial extractor, 6-output waveguide), (b) the phase-space distribution of electron beam, (c) average power versus time, and (d) spectrum of output power.