<inline-formula> <tex-math notation="LaTeX">$L$ </tex-math> </inline-formula> -Band Relativistic Traveling Wave Oscillator Based on a Circular Corrugated Waveguide

Abstract

A coupling impedance ( $Z_{0}\approx 9\Omega $ ) between a relativistic electron beam and a fundamental harmonic of a TM01 wave slowed down to the speed of light in a circular corrugated waveguide is calculated. The geometry of a relativistic ( $\approx 420$ keV) traveling wave oscillator (TWO) with an operating frequency of 1.25 GHz is optimized using this calculations by the fully electromagnetic particle-in-cell (PIC) code KARAT. The transient time obtained in PIC simulations is $\approx 26$ ns. A microwave power of 340 MW is also obtained in PIC simulations at an electron beam current of 3.0 kA in strong ( $\approx 0.3$ T) and weak ( $\approx 0.08$ T) guiding magnetic fields, which corresponds to the oscillator efficiency $\approx 27$ %.