An electric circuital analysis of laboratory plasma sheath fluctuations and propagations

Abstract: The effective inductive (L), capacitive (C), and resistive (R) behavior of a plasma sheath in a conjoint coupled form is well familiar among plasma physics communities. A dynamic sheath instability in laboratory plasmas is systematically modelled herein as an electrical series-resonance LCR circuit of the above kind. It theoretically yields experimentally observed findings on coexistent plasma sheath oscillation, electric current perturbation, and subsequent plasma sheath waves (PSWs). The plasma current in the LCR circuit formalism is allowed to undergo linear (small-scale) spatiotemporal perturbations about its homogeneous equilibrium state. The oscillating sheath triggers ion-acoustic wave excitation in the bulk plasma through sheath-induced energy transfer processes. The obtained results could be applicable mainly in understanding electromagnetic communication antennas, ion energy modulation processes, diverse plasma probe diagnostics, etc.