Travelling Wakefield Tube: THz Source Powered by Nonrelativistic Electron Beam

TL;DR

This paper proposes a compact, portable THz source using a nonrelativistic electron beam passing through a dielectric structure, achieving tunable high-power emission with improved efficiency for practical applications.

Contribution

It introduces a novel THz generation scheme utilizing a nonrelativistic 200 keV electron beam, enabling a compact and tunable THz source with significant power gain and efficiency.

Findings

Operates between 0.4-1.6 THz frequency range.

Achieves a power gain of five times.

Average efficiency of 6.8%.

Abstract

High peak power, tunable, narrowband terahertz emitters are becoming sought after given their portability, efficiency, and ability to be deployed in the field for industrial, medical, and military applications. The use of accelerator systems producing THz frequencies via Cherenkov radiation, generated by passing an electron beam through a slow-wave wakefield structure, is a promising method to meet future THz requirements. To date, efforts have been dedicated to analysis and design of sources utilizing laser seeded bunched electron beam drivers with relativistic energies beyond 5 MeV. Presented here is a wakefield THz generation scheme based on passing a long quasi-dc nonrelativistic beam (200 keV) through a dielectric loaded travelling wave structure. Reduced energy allows for compactness and portability of the accelerator as the size and weight of the dielectric slow wave structure is vanishingly small compared to the accelerator unit. The presented scheme can serve as a tunable high peak power THz source operated between 0.4-1.6 THz and produces power gain by a factor of five with an average efficiency of 6.8\%.