Propagation characteristics of terahertz wave in hypersonic plasma sheath considering high temperature air chemical reactions

Abstract

In this work, the propagation characteristics of terahertz wave in the hypersonic plasma sheath is demonstrated and analyzed based on the realistic vehicle model and the high temperature air thermal chemical reactions. Based on the simulated flow field distribution around the hypersonic vehicle, the electron densities of the plasma sheath at different Mach numbers are calculated by adopting the equilibrium constant method of the 7-species reacting air model. And then the propagation model of terahertz wave in plasma sheath is established using the scattering matrix method. The calculated and simulated results show that the plasma electron density is strongly influenced by Mach number, and the higher frequency and smaller incident angle of terahertz wave are advantageous for a better transmittance and lower loss. Furthermore, the effects of an external magnetic field on the propagation characteristics of left-hand and right-hand polarized terahertz wave in plasma sheath are studied. The external magnetic field indeed reduces the transmission loss of the left-handed wave. This work promises that terahertz waves have good potential applications in the detection and the communication for the hypersonic vehicles in plasma sheath.