Design and evaluation of dual inlet ICP torch for low gas consumption

In this study, we concentrated on improving the vortex flow uniformity, which was considered as a key factor for our new ICP torch design. To obtain a uniform vortex flow with lower plasma gas consumption, our new ICP torch had a dual gas inlet, and convertibility for helium and argon ICP. With this modification, helium ICP was able to operate with a 10-20% lower plasma gas flow rate than our previous torch. To confirm the effects of the dual inlet, the flows were compared using a high-speed video system, and the noise-power spectra of the emission line spectrum of helium and argon were measured. As the result of these measurements, the ICP with the dual inlet had higher frequency of plasma rotation than that of the single inlet torch. It is shown that the dual inlet gives less damping of the plasma gas flow and that adequate vortex flow can be generated with lower plasma gas consumption.