Self-organization of double layer structures in glow discharge regime

Numerous research investigations have been carried out on the development of multiple charged layers in hollow cathode discharge in recent years. However earlier research failed to investigate the underlying mechanism using a controlled plasma source in the formation of multiple double layers (MDLs) and complex anode spots. The present study primarily focus on the role of negatively biased rectangular grid acting as a secondary plasma source placed between the asymmetrical cathode and the anode under an external magnetic field. The trapping of the non-thermal electrons by the negatively biased grid results in the nonlinear dissipation of energy in the plasma column, leading to the formation of MDLs in different Negative Differential Resistance (NDR) regimes close to the anode. The study also emphasizes the self-organization of MDLs and the associated sheath plasma interactions during different glow discharge regimes. Due to the insufficient transport of electrons from the biased rectangular grid, the sheath structure forms near the anode resulting in the charge localization and complex structure formations. With the enhancement of applied potential, the electrons surpass the barrier potential of the grid and the sheaths develop into concentric anode spots. Further nonlinear approaches confirm the formation of MDL enhancing the sheath dynamics and the associated NDR phenomenon to understand sheath- plasma instabilities present in the system. Various plasma applications related to self-organized MDLs includes medical technologies and nanomaterial synthesis.