A new technique for studying gas-flow dynamics in unlit ICP torches is presented. This technique allows direct visualization of the gas-flow pattern of any one of the three argon flows employed by an ICP torch. The gas-flow patterns are observed by introducing a light-scattering medium into one of the argon flows and passing a thin plane of light through the gas above the torch. Because a thin plane of light is employed for visualization, direct radial and vertical gas-flow patterns can be observed in a direction perpendicular to the plane. Flow patterns for the coolant, plasma, and central gases were studied, as was the effect of argon flow rates in conventional and low-argon-consumption torches.
Alfred G. Childers and Gary M. Hieftje, "A Novel Light-Scattering Technique to Study Gas-Flow Dynamics in an ICP Torch," Appl. Spectrosc. 40, 680-683 (1986)