Generation of terahertz electromagnetic radiation in a beam-driven turbulent plasma

Powerful terahertz electromagnetic radiation has good prospects for various technological applications. Motivated by this we investigate terahertz emission during strong relativistic electron beam (REB)-plasma interaction¹. In this paper we present results of theoretical considerations and computer simulations on the generation process of such radiation in a turbulent magnetized plasma driven by a powerful REB. It is well known that plasma turbulence produces intense electromagnetic emission at the fundamental plasma frequency and its second harmonic. The latter reaches the terahertz frequency range in rather dense plasmas. In order to estimate the power and spectral width of second harmonic plasma emission generated during REB-plasma interaction we use a theoretical model² which allows to calculate emission produced by coalescence of un-trapped Langmuir waves in the long-wavelength range of strong plasma turbulence. This model is found to explain the results of laboratory REB-plasma experiments at the GOL-3 multi-mirror trap¹. In particular, we managed to predict the measured power and polarization of emission.