Experimental investigation of breakdowns in gliding arc system

The phenomena of breakdowns in gliding are device (GLIDARC) are studied exp erimentally for air, argon, nitrogen, carbon dioxide and hydrogen. Special emphasis is placed on the thermal and dielectric kinds of breakdowns and th e conditions of their occurrence. The results show that the breakdown betwe en the narrowest points of the gliding are electrodes is submitted to the P aschen's law but is strongly affected by the conditions of the cathode surf ace, the gas flow injected in direction perpendicular to the axis of the di scharge and gas purity. The results agree with the well-known general relat ions of voltage breakdown for different gases. The experiments demonstrate that the breakdowns between are and electrode, for high flow rate, are almo st always dielectric whereas the breakdown between the parts of are is ther mal origin. For low flow rate, the thermal breakdowns between are and elect rode can occur. The analysis of voltage breakdown Delta U, time breakdown d r and the parameter of Delta U/Delta t shows that the breakdowns in gliding are do not always result to simple mechanism dielectric or thermal breakdo wns.