Terahertz electromagnetic radiation based on the interaction between a self-modulated electron beam and plasma wakefield

Abstract

This particle-in-cell simulation study finds that the system of a long relativistic electron beam passing through an overdense plasma can produce high harmonic terahertz electromagnetic radiation. In this process, the electron beam is self-modulated to create a periodic electromagnetic structure which will resonate with the plasma wakefield and excite the electromagnetic instability in the nonlinear stage of the self-modulation. The study also finds that when the radiation is achieved, the self-modulated electron beam will be destroyed due to the self-consistent interaction among the radiation, the electron beam, and the plasma. Meanwhile, the radiation will gradually attenuate, which also coincides with the physical explanation of the radiation.

Novel mechanism for terahertz radiation by oblique colliding of two electron beams in plasma

“…Recently, a new kind of high-power THz source, called electron beam-plasma system (EBPS) has attracted wide attention [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. This THz source does not have a damage threshold as the plasma is in a highly ionized state.…”

“…Previous experiments have successfully observed powerful THz radiation from EBPS in a large magnetic confinement plasma device [16][17][18]. Meanwhile, various related THz radiation mechanisms have also been investigated [19][20][21][22][23][24][25][26][27][28][29]. It can be found that all the previous studies adopt linear schemes considering a single beam or two counterstreaming beams passing through a plasma column.…”

Second harmonic electromagnetic emission in a beam-driven plasma antenna

“…Generation of electromagnetic (EM) waves near harmonics of the plasma frequency 𝜔 𝑝 during collective beam-plasma interaction is a well known phenomena that is frequently observed in both space and laboratory plasmas. Presently, processes of linear and nonlinear conversion of beam-driven electrostatic plasma waves into EM radiation are actively studied in relation to solar radio bursts [1][2][3][4] and the problem of high-power terahertz generation [5][6][7][8][9]. If the beam-to-radiation power conversion in the latter problem is increased up to a few percent, radiation sources based on multi-GW electron beams will be able to achieve the record gigawatt level of terahertz power.…”

Terahertz radiation emission using plasma‐filled dielectric liner with the effects of pre‐modulated relativistic electron beam

“…The emission of THz radiation by the photoelectron current induced by the ionization of a gas due to non-linear mixing of the fundamental and second harmonic of ultra-short laser pulses was studied analytically by Kim et al [15] Recently, the excitation of electromagnetic waves by the interaction of a self-modulated electron beam and an over-dense plasma was studied by Yang et al [16] by using particle-in-a-cell (PIC) simulation. Because of the resonance between the plasma wakefield and the electron beam, plasma oscillations are amplified to generate THz radiation.…”