Experimental analysis of a DC–RF hybrid plasma flow

A direct current (DC)–RF hybrid plasma flow has a very complex flow structure because of the interaction between a DC plasma jet and a RF-ICP flow. Therefore, flow control of a DC–RF hybrid plasma flow is very important to enhance its characteristics such as temperature, stability and plasma flame length. In this paper, we clarified the linear interaction between the flow condition and plasma characteristics, and then optimized its operating condition. A DC–RF hybrid plasma flow becomes stable and is elongated with decreasing the central gas ratio. It also becomes stable with increasing the swirl gas. Moreover, a large amount of N2 gas can be injected with the central gas.