THz wave propagation in the stagnation region of reentry plasma sheath

By using two-dimensional particle-in-cell simulations, we demonstrate a terahertz (THz) wave propagating in the stagnation region of a reentry plasma sheath. When a THz wave propagates in the plasma sheath, the frequency blue shift is initiated as the wavelength is compressed. Attenuation is observed due to energy transfer from the THz wave to the plasma internal energy. Electrons are first accelerated mostly via oscillating in the electric field and partially via the wake field and then deliver their energies to the other particles via collisions. Detailed discussions show that increasing the intensity and frequency of the THz wave results in a higher transmission coefficient, which indicates that high power and high frequency methods are useful for communication blackout mitigation. This investigation of THz wave transmission in plasma will facilitate the mitigation of radio frequency blackout in spacecraft reentry in earth’s atmosphere communication.