Search

Discharge structure refers to the morphology of different plasma quantities, such as electron temperature, reaction rate, plasma potential, mass flux, net charge and species density, which are determined by plasma transport mechanism and chemical processes. This morphology is rather difficult to refine in complex electronegative plasma for it is contained in a multiple-physics-field coupled system. Regarding this difficulty, the combination of self-consistent simulation, theory analysis and experimental diagnostic of this system is needed. In the scope of present article, the fluid simulation and analytic theory are utilized to investigate the Ar/Cl2 inductive plasma, via a cyclic tuning of discharge pressure and feedstock gas content parameters when fixing the power. Classic discharge structure (e.g., delta, parabola, flat-top, and hollow) and specific discharge mechanisms (e.g., self-coagulation, physics coagulation, de-coagulation, grouping behavior and the ambi-polar diffusion of triple species) are revealed. Besides, the two types of discharge stratification, i.e., space and species, are presented. Many non-neutralities are generated during the transport process of electronegative plasma when it gives rise to the discharge structure, which are summed and analyzed for better understanding the plasma., Comment: 36 pages, 29 figures, 1 table

The discharge structure of inductively coupled plasma is studied via fluid simulation and analytic theory collaboration. At low pressure, the discharge is stratified by the double layer, which is modelled as dipole moment. The parabolic profile is formed in the discharge core when recombination loss is negligible and both the electron and anions are the Boltzmann balanced. At increasing the pressure, the main characteristics, i.e., parabolic, elliptic and flat-topped profile, are experienced, predicted by the simulation and analytics. Self-coagulation is accompanied at all considered pressures. It is more a chemistry process and provides new means of constricting plasma. At its influence, electron density deviates from the Boltzmann equilibrium. For satisfying the neutrality of bulk plasma, the ambi-polar self-coagulation mechanism is suggested. At high pressure, the self-coagulation-to-coil scheme causes the mass point behavior in the plasma. Minor cations re-self-coagulate at certain conditions and the correlation with the celestial bodies formation is hypothesized., Comment: 71 pages, 64 figures, submitted to Physics of Plasmas