Influence of carbon dioxide on the radial temperature distribution in an argon arc

The temperature profiles in wall-stabilized atmospheric-pressure arcs in pure argon and in argon-carbon dioxide mixtures have been obtained at currents of 5-40 A and for molar percentages of CO2 ranging from 0.9 % to 25 % using spectroscopic techniques. With the addition of CO2 to a pure-Ar are, we show the formation of a core of higher temperatures with a larger gradient of the radial temperature distribution at the are centre. These investigations show that the addition of even a few percent of CO2 to Ar has a marked effect both upon extinction of the are according to current values and upon the temperature profiles. Few measurements have been done in Ar-CO2 mixtures in a wall-stabilized are.