Lifetime evaluation of weakly ionized plasma channel by accumulation effect of charged particles by means of laser absorption

The density of weakly ionized plasma and the lifetime for laser-triggered lightning are improved by using a KrF excimer laser with a high repetition rate of the order of kilohertz. We have studied how to create a weakly ionized plasma channel with the plasma density of 1013 cm−3 and the long lifetime of the order of milliseconds in order to trigger and guide lightning discharge efficiently. The density of a weakly ionized plasma channel is 1013 cm−3 and the plasma channel has a long lifetime of the order of milliseconds, which were achieved by utilizing the accumulation effect of charged particles generated by the high-repetition-rate laser. Moreover, it is clarified that the dominant mechanism of decay of plasma generated the high-repetition-rate laser was ion-ion recombination between N+ and O−.