INVESTIGATION INTO THE OPERATING CHARACTERISTICS OF A MICRO-ARC ATMOSPHERIC-PRESSURE GLOW-DISCHARGE

Details of the processes occurring during sample atomization from a ″microarc″ discharge have been studied photometrically, by use of high-speed color cinematography and through current-voltage waveforms. The microarc studied here is an atmospheric-pressure inert-gas glow discharge supported between 0. 25 mm diameter tungsten wires; quiescent argon-1% H//2 provides reactive-sputtering conditions and improved behavior in the presence of oxygen impurities. Excitation temperatures of ca. 5000 degree K are measured for the argon glow. Samples of Na, Al, and Sr illustrate the influence of volatile, refractory, insulating, and electron-emitting sample properties on the temporal-spatial-electrical behavior of the discharge.