Method to penetrate through the overdense plasma sheath: Mode conversion in nonuniform plasmas with two-temperature electron population

Abstract

Electromagnetic wave (EMW) penetration through an overdense plasma sheath is a critical subject in solving the “communication blackout” issue. Based on the numerical electron fluid numerical simulations, the linear mode conversion between EMW and electron acoustic waves (EAWs) was examined in the unmagnetized nonuniform plasma sheath with two-temperature electron population. The first resonant position of EMW in the plasma sheath is crucial to stimulate EAW efficiently, while the second one plays an important role in electromagnetic radiation from EAW. Owing to the mode conversion and EAW propagation, a channel can be opened in the overdense nonuniform plasma sheath for EMW. The transmission efficiency of EMW will be reduced remarkably for lacking a low density region where the mode conversion takes place.