Swelling Kinetics Of Nanosecond Pulsed Plasma Induced By Air And Metal

This article from the experimental study of air and metal nanosecond pulse-induced plasma expansion dynamics and theory of the expansion process of the plasma was analyzed theoretically.First, the establishment of a high-speed camera to capture a single laser pulse ICCD breakdown of air to the metal target and focus the imaging experimental device, the generated plasma to obtain the evolution of the space for the plasma generated under different conditions the displacement and velocity variations were analyzed discussed.Second, the establishment of a single laser pulse was observed by fluorescence breakdown of air to the metal target and focus experimental device for detecting light generated by plasma processes of energy absorption.Observed in imaging the evolution of the plasma in the space, you can know the main pulse laser breakdown in air and focused on metal targets when originally formed in the plasma period, the role of the main pulse energy of greater expansion velocity of the plasma greater period of time, the large energy of the shock wave energy in the expansion rate is smaller than the expansion rate was significantly attenuated, which is leading to the collapse of the plasma channel of the reasons. Same conditions in other cases, the focus to the copper target expansion velocity of the plasma generated minimal, and the breakdown of air plasma generated when the maximum rate of expansion.Observed using fluorescence in single pulse laser breakdown of air and focused onto a metal target experiments, we obtained when the main pulse energy in certain circumstances the breakdown of air generated plasma diffusion distances, the main pulse laser energy was50mJ breakdown case of air, the plasma expanding from the axial direction of the laser beam is incident up to3mm, and the main laser pulse energy of50mJ case, the focus to an aluminum target, the diffusion distance can reach2mm, and the same main pulse laser irradiation conditions in the copper target, the diffusion distance of less than lmm, which shows the effect of different target under the same laser energy, resulting in the expansion of the plasma is not the same distance, the breakdown in the air, respectively, the focus aluminum target and focus to the copper target in the case, the breakdown of air plasma generated farthest expansion.