On the Radiation from an Argon Plasma at One Atmospheric Pressure

The argon plasma jet at one atmospheric pressure has strongly emitted radiations from ultraviolet to infra-red zone. The measurements with spectrometer were performed to obtain the spectrum energy distribution for D. C. argon jet. The thermoelectric radiation probe was developed and radiant power from the jet was measured. Experiments were made at arc currents from 40 up to 160 A in argon gas flow rate of 10 1/min or 20 1/min. Radiation intensity mainly depended on arc currents and the strong radiation lay in the wavelength above 4200A^^°. Especially, the concentration of line spectrum was in the wavelength from 4200A^^°to 4400A^^° or 7900A^^° to 8100A^^°. As power input was increased, the wavelength to maximum intensity was moved to the shorter. Intensity depended on the distance (L) from nozzle exit : for L<4mm, the intensity decreased rapidly