Stimulation of Waves and Instabilities in Response to Irradiation of Electromagnetic Fields into Plasmas
Authors
Abstract
Plasma is a unique phase of matter constituting positively or negatively charged atoms, excited atoms, neutral atoms, electrons, radicals, etcetera displaying a unique role in the nuclear fusion research besides studying electrical discharges in the domain of switching devices and biomedical applications lately. We discuss in this extensive proposition the fundamental plasma characteristics such as Debye length, plasma oscillations, plasma sheath and condition for sustainability and confinement of plasmas, besides examining the elementary waves in plasmas namely zero waves, electron plasma wave and ion plasma wave. The inherent electron plasma wave and ion plasma wave is associated with the driving of plasma currents which in turn depends upon the density perturbation and thermal velocities of the electrons and ions. The application of external electromagnetic radiation such as laser (pump wave) into the plasma modifies the dispersion relations of electron and ion plasma wave, respectively. The laser stimulates a plethora of waves in the plasma and undergoes remarkable physical phenomena such as self-focusing and filamentation of laser beams. The excitation of sideband waves of the laser beams into the plasma plays a key role in imparting ponderomotive force on the electron plasma waves leading to turbulence in the plasmas due to coupling of the waves. The oscillatory velocity of the electron due to pump wave, plasma density perturbation, ponderomotive force and current densities are associated with the excitation of instabilities in the plasma. Conclusively, such waves and instabilities in unmagnetized and magnetized plasma is comprehensively studied and concluded by proposing the investigation of unexplored twisted electromagnetic wave-plasma interaction.
