Incoherent scattering ion line spectra of vortex beams by magnetized ionospheric plasma with bi-Maxwellian distribution

Abstract Incoherent scattering theory is one of the important means of plasma parameter diagnosis. The incoherent scattering of vortex beams carrying orbital angular momentum can bring new incremental information to plasma diagnosis. Based on the angular spectrum theory of Bessel vortex beams and the theory of incoherent scattering, this paper studies the incoherent scattering of the ionospheric magnetized plasma to vortex electromagnetic waves under the bi-Maxwellian distribution along the magnetic field drift. The numerical results show that when the angle between the scattering wave vector and the magnetic field direction is small, the ion spectral lines have an obvious frequency shift. When the angle is close to 90°, the ion line spectra produce harmonic oscillation, and the drift speed restrains this oscillation phenomenon. The linear Doppler shift will shift the spectral line as a whole, while the rotating Doppler shift of the vortex beam will weaken the spectral line oscillation. This work may provide a possibility for further research on the scattering of vortex beams by magnetized plasma and the development of ionospheric plasma irregularities parameter inversion.