Evaluation of cooling gas for argon/helium compatible ICP

In a new argon/helium compatible ICP torch designed to reduce plasma gas consumption, a cooling gas is exhausted in the same direction as the plasma, which causes concern about an immixture of both gases and air. In this study, the effect of a cooling gas difference and the flow rate on the emission properties of Ar and He ICP were investigated by measuring the emission intensities of OH, N-2 and Ar. When an appropriate cooling gas and flow rate were chosen, the background emission caused by the air immixture was reduced.