Excitation and kinetic equilibrium in an argon inductively coupled plasma—II: Introduction of aerosol flow

• Published in: Spectrochimica acta. Part B: Atomic spectroscopy 1989, Vol.44 (4), p.395-410
• Main Author: Miller, G.P.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma devices
• ISSN: 0584-8547; 1873-3565
• DOI: 10.1016/0584-8547(89)80043-6

The introduction of an aerosol flow (argon only) axially through an inductively coupled plasma is shown, by means of a relaxation method, to cause a deviation from excitational equilibrium across the entire plasma radius. Increasing this flow from 1 to 21 min appears to return the plasma to a state of excitational equilibrium, but the temperatures obtained are inconsistent with the validity of Saha's equation, indicating a non-Boltzmann distribution of the Ar I excited states. The effects of the introduction of aerosols containing various molecular samples through the centre of the plasma of an inductively coupled argon plasma torch on the state of kinetic and excitational equilibrium are then investigated. Aerosols of argon +4% H 2, 4% air, H 2O and 1% KCl in aqueous solution were introduced through the central channel of the plasma. Their effect on the state of kinetic and excitational equilibrium of the plasma is found to be relatively insignificant compared to that caused by the aerosol gas flow.