Research on air gap discharge induced by axial injection of nanosecond laser light

In this paper, the experimental study on air gap discharge induced by axial injection of nanosecond laser light under DC high voltage was carried out. The effects of laser energy, electrode distance and air density on the lowest reliable trigger voltage of air gap were investigated. The results show that the lowest reliable trigger voltage decreases exponentially with the increase of laser energy when the electrode distance is fixed. The smaller the electrode distance is, the lower is the ratio of the lowest reliable trigger voltage to the self-discharge voltage. The maximum reduction of the lowest reliable trigger voltage is closely related to the electrode distance. With the decrease of air pressure, the lowest reliable trigger voltage is reduced, and the ratio of lowest reliable trigger voltage to self-discharge voltage is increased slightly.