About the influences of gas composition and generator frequency on the formation conditions and parameters of vortex tube in the RF inductively coupled plasma

The results of numerical simulation of plasma flow in the channel of technological radio frequency inductively coupled plasma (RF-ICP) with three coils are presented. The generator frequency is varied from 1.76 to 13.56 MHz. The pure argon or Ar/H₂ mixture are considered as the working gas. The volume fraction of hydrogen in Ar/H2 mixture is varied from 0 to 10%. The distributions of gas-dynamic parameters of plasma flow are calculated. It is shown that when the amplitude of discharge current exceeds a critical value (depends on volume fraction of hydrogen), the states of plasma flow transform from potential to vortical patterns, in which a toroidal vortex is found in front of the inductor zone. The dependencies of critical current on the generator frequency and volume fraction of hydrogen are established. The influences of generator frequency, volume fraction and discharge current on the intensity and coordinate of vortex tube are determined.