Ablation Effect On An Impulse Discharge Induced By A Laser Plasma Channel

In order to develop a technique to induce a negative impulse discharge by a laser-ionized channel in a rod-to-rod electrode configuration, the ablation effect on the induction has been examined. Single irradiation by a high-power CO2 laser on the surface of the copper high-voltage electrode produced a luminous plasma plume. This ablation plasma was used for a discharge induction by an ionization channel created by a XeCl laser. It was found that the ablation enhances the trigger and guide effect for induction of a long gap discharge. The guide length was elongated approximately twice. The ablation plasma bead reduced the 50% sparkover voltage and the sparkover time. Electrical discharge leaders were observed by a flaming image converter camera. The ablation plasma bead made an early start of the leader from the high-voltage electrode and accelerated the leader advancement.