Flow modelling and gas heating inside a profiling channel of an electric arc plasma torch

This paper presents a theor. model for the numerical anal. of the acceleration and heating of a gas by an elec. arc in a profiling channel with a diffuser anode. The thermal parameters and transport coeffs. of helium were detd. and the approximative expression for their calcn. in a broad range of temp. (0,3-100) kK and pressures are proposed. The calcn. and study of the effect of the thermal nonequil. plasma on the characteristics of the cylindrical arc were carried out. The results of the calcns. were compared with exptl. data and calcns. obtained from an equil. plasma model. [on SciFinder (R)

Atomic hydrogen level populations and hydrogen dissociation degree in an expanding thermal plasma

Optical absorption spectroscopy has been applied to measure the abs. population densities of the first excited states levels of at. hydrogen H*(n = 2) and argon Ar*(4s) in an expanding cascaded arc plasma in a hydrogen-argon mixt. It is demonstrated that the method allows us to det. both H*(n = 2) and Ar*(4s) abs. d. radial profiles for H2 admixts. in Ar ranging from 0.7 to 10% with good accuracy. It has been shown that the d. of hydrogen excited atoms H*(n = 2) serves as an indicator of the presence of argon ions and hydrogen mols. in the expanding plasma. A kinetic model is used to understand evolution of H*(n = 2) d. in the expansion, and to est. the total at. hydrogen population d. and hydrogen dissocn. degree in sub- and supersonic regions of the plasma. [on SciFinder (R)

Atomic hydrogen level populations and hydrogen dissociation degree in an expanding thermal plasma

Optical absorption spectroscopy has been applied to measure the abs. population densities of the first excited states levels of at. hydrogen H*(n = 2) and argon Ar*(4s) in an expanding cascaded arc plasma in a hydrogen-argon mixt. It is demonstrated that the method allows us to det. both H*(n = 2) and Ar*(4s) abs. d. radial profiles for H2 admixts. in Ar ranging from 0.7 to 10% with good accuracy. It has been shown that the d. of hydrogen excited atoms H*(n = 2) serves as an indicator of the presence of argon ions and hydrogen mols. in the expanding plasma. A kinetic model is used to understand evolution of H*(n = 2) d. in the expansion, and to est. the total at. hydrogen population d. and hydrogen dissocn. degree in sub- and supersonic regions of the plasma. [on SciFinder (R)