Investigation of the argon arc binding to the lanthanated tungsten cathode

Pyrometric and spectroscopic investigations of lanthanated tungsten cathode in argon arc plasma discharge at atmospheric pressure are reported. The distribution of the surface cathode temperature was measured. Calculations and estimates of the emission current density are performed. Experimental data of the total current density are compared with the obtained results of estimation. The possible reasons for the discrepancy between the experimental and theoretical values of the total current were discussed

Mechanism of mass expulsion from the surface of a pure tungsten cathode during dc arc initiation

In this work the destruction mechanism of a pure tungsten cathode during the initiation of direct current arc is studied. The experimental work shows that the cathode resides in liquid form during the initiation of the arc, and the process of its destruction happens by ejecting droplets from its surface with the following explosion. The average speed of the ejection and the temperature at the explosion points microseconds before the explosion were registered. A mathematical model is proposed explaining the reason behind the droplets formation

One more study of argon arc binding to pure tungsten cathode

Pyrometric and spectroscopic investigations of pure tungsten cathode in argon arc plasma discharge at atmospheric pressure are reported. The distribution of surface cathode temperature and the radial distribution of plasma temperature at different distance from the cathode tip were measured. We conducted a comparison between our work and other studies on arc discharges where cathodes from lanthanated (W-2% La2O3) and thoriated (W-2% ThO2) tungsten were used