Generation of powerful terahertz emission in a beam-driven strong plasma turbulence

TL;DR

This paper investigates how strong plasma turbulence driven by high-current relativistic electron beams can generate powerful terahertz radiation, with potential laboratory applications reaching megawatt power densities.

Contribution

It presents a theoretical model explaining terahertz emission via upper-hybrid wave coalescence in beam-driven plasma turbulence, matching experimental conditions.

Findings

Terahertz emission power density can reach 1 MW/cm³.

Conversion efficiency of beam energy to terahertz radiation is about 1%.

The model accurately describes experimental observations in mirror traps.

Abstract

Generation of terahertz electromagnetic radiation due to coalescence of upper-hybrid waves in the long-wavelength region of strong plasma turbulence driven by a high-current relativistic electron beam in a magnetized plasma is investigated. The width of frequency spectrum as well as angular characteristics of this radiation for various values of plasma density and turbulence energy are calculated using the simple theoretical model adequately describing beam-plasma experiments at mirror traps. It is shown that the power density of electromagnetic emission at the second harmonic of plasma frequency in the terahertz range for these laboratory experiments can reach the level of 1 ${MW/cm}^3$ with 1% conversion efficiency of beam energy losses to electromagnetic emission.