Spectroscopic Diagnostic and Electrical Characteristic of a Converging-Diverging Plasma Torch at Low Pressure Condition

A new anode nozzle with converging-diverging shape designed for low pressure condition used to produce the plasma jet. The emission spectroscope diagnostic method is applied to calculate the electron temperature by Ar I neutral species' Boltzmann plots. The efficiency and voltage-current characteristic of the plasma torch were studied. The results showed that with the increase of the current intensity the electron temperature increase a lot. With the increase of the input power the efficiency of the plasma gun rise a little bit and the electric characteristic of the plasma gun is dependent on the content of hydrogen. (paper)