Spatial distributions of atomic and molecular species in the inductively coupled argon plasma

Abstract

Spatial distributions of various atoms and molecules in the inductively coupled argon plasma (ICP) has been studied by modeling kinetic reactions between plasma components. Calculations for the excited level populations of hydrogen atom and nitrogen molecule were carried out in order to determine their ground state number densities from temperatures and absolute emission intensities. Number densities of other species were estimated by assuming thermal equilibrium between dissociation and recombination processes. The spatially resolved profiles clearly obtained showed that water introduced into the plasma as an aqueous solution was almost completely decomposed to atomic hydrogen and oxygen, while nitrogen rather existed as molecules because of the relatively high dissociation energy. In addition, air entrainment from the surrounding atmosphere and sideward diffusion of species were discussed in terms of the spatial characteristics of the ICP.