Abstract
Hydrogen Hβ spectrum intensity distributions were measured at three coordinates along the axis of an rf Ar-H2 plasma torch with a central Ar flow rate of either 0 or 3 l/min. The distributions were inverted to emission coefficient profiles by Abel inversion. Considering that the half widths of the profiles depended only on Stark effect, we calculated electron densities to obtain temperature distributions under the assumption of LTE (local thermodynamic equilibrium). On the other hand, we calculated plasma temperature distribution by the modeling work that assumed laminar flow and LTE state in whole plasma regions. Using the temperatures and chemical species concentrations obtained by the modeling work, we calculated electron densities under the assumption of LTE. Moreover, we observed plasma edges and cold-gas channel generated by the central flow macroscopically by photographing. Using above three method, we tried to elucidate electron density and temperature distributions of our rf Ar-H2 thermal plasmas comprehensively.
