A compact, high-power THz source: Concept & simulation

Many applications of THz radiation remain impractical or impossible due to an absence of compact sources with sufficient power. This paper presents a source concept capable of high power in the THz range. The interaction occurs between an annular electron beam and a cylindrical grating. The grating surface-wave produces strong beam bunching and generates significant high-frequency rf. Parametric studies using the MAGIC simulation code explored grating geometry, beam current, voltage, magnetic field, tuning bandwidth, harmonic generation and controlled feedback. Several multi-grating configurations were also simulated. In contrast to planar grating, simulations showed rf growth at current densities as low as 50 A/cm². Results indicate a compact device could generate multiple tens of watts output above 1THz.