Resonant absorption of incident electromagnetic waves in collisional inhomogeneous plasma slabs

• Published in: AIP advances 2019-09, Vol.9 (9), p.095020-095020-10
• Main Authors: Li, Bowen, Nie, Qiuyue, Wang, Xiaogang, Wang, Zhibin, Mao, Aohua, Chen, Peiqi
• Format: Article
• Language: English
• Subjects: Charged particles; Electromagnetic radiation; Energy absorption; Energy dissipation; Neutral particles; Plasma; Plasma oscillations; Resonance scattering; Wave propagation
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.5113689

Resonant absorption is a process that electromagnetic (EM) energy is converted to plasma energy with a mode conversion on the resonant layer where the incident EM wave frequency equals to the local frequency of a plasma normal modes. With a finite collision between charged and background neutral particles in a plasma, the plasma oscillation is dissipated to widen the resonance layer and heat the plasma. In this work a modified scattering matrix methods (SMM) are applied to study the effects of the collision frequency, incident angle, and plasma thickness on resonant absorption. We analyze the energy absorption caused by resonance in comparison with collisional absorption for different parameters. It is found that the resonant absorption dissipates about nearly half of the incident EM energy in an overdense inhomogeneous plasma when the collision is weak, and the rest half portion is reflected. If the collision is strong, however, the collisional absorption is then more significant than the resonant and affects the entire wave propagation process.