Laser-induced breakdown experiment in nitrogen

The characteristics of laser-induced breakdown in nitrogen at a wavelength of 1064nm were investigated with a 10-ns pulsed laser generator. The threshold field of nitrogen decreases as the pressure increases, and the experimental threshold intensities at the lower pressure were in good agreement with experimental values measured by Striker and Parker in 1982. The delay and jitter decreases while increasing the laser energy or the ratio self-breakdown voltage. Increasing gap field can accelerate the closing rate of switch. Under the conditions of average gap field 35kV/cm, ratio of laser focal length to gap length 0.065 and laser-induced energy a little greater than threshold intensities, experimental results of 25-ns delay and 20-ns jitter of switch were approached. Thus experimental results indicated that, using laser-induced breakdown switch, multi-module high power pulse devices could produce sequential pulses with inter-pulse delays of tens nanosecond.