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

Abstract

Abstract.Generation of terahertz electromagnetic radiation due to coalescence of upperhybrid 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.

Beam-plasma system as a source of powerful submillimeter and terahertz radiation (experimental and theoretical studies)

“…The same tendency is predicted by the recently proposed theoretical model [6,7] in which this emission is produced by coalescence of long-wavelength upper hybrid waves. According to this model, the power pumping into upper hybrid waves by the electron beam is saturated at a constant level …”

“…The Figure 3 also demonstrates polarization of the plasma emission in these two spectral ranges. This experimental result has good coincidence with the result of a theoretical analysis given in [6,7].…”

“…Using the theory [6,7], we have calculated the angular distribution of radiation power of the doubled frequency that is presented in Fig. 7.…”

Properties of sub-THz waves generated by the plasma during interaction with relativistic electron beam

“…This plasma gradient may be result density fluctuations caused, for example, by ion plasma waves. As to the high-frequency band 380÷500 GHz, this emission, on our opinion, is result of the coalescence of two upper hybrid plasma waves to electromagnetic one [9][10][11].…”

Mechanisms of enhanced electromagnetic emission in laboratory beam-plasma systems

“…For many years, the scientific program of the GOL-3 open trap was focused on mechanisms of turbulent plasma heating under the injection of high-power (10 − 20 GW) electron beams. Recently, it has been noticed that the parameters of such a powerful device are well suited for generation of terahertz radiation [1]. Even for the relatively low conversion efficiency 1 − 10%, the power of such a terahertz source could reach the gigawatt level (0.1 − 1 GW).…”