Propagation characteristics of THz waves in space-time inhomogeneous and fully ionized dusty plasma sheath

Abstract

When a hypersonic vehicle flies in near-space, the electron density of the plasma surrounding the aircraft is inhomogeneous and varies with time. Ablation occurs around the vehicle as the temperature rises. Therefore, investigating the propagation characteristics of electromagnetic (EM) waves in a space/time inhomogeneous and fully ionised dusty plasma sheath is important. In this article, a space/time inhomogeneous dusty plasma sheath model is first established. The expression of the dielectric coefficients of weakly collisional and fully ionised dusty plasma sheath is adopted. The shift-operator finite difference time-domain method is used to calculate the reflection and transmission coefficients of different dusty particle concentrations and radii, changes in electron density with time, electron temperatures and ion charges in the terahertz (THz) band. Finally, the propagation characteristics of THz waves with different electron density distributions at eight re-entry heights are analysed. Results show that increasing the incident wave frequency can effectively improve the effects of dusty particle concentration and radius, electron temperature and ion charge on the transmission of the EM wave. Different electron density change forms and electron density distributions significantly influence the propagation properties of THz waves.