Investigation of stark shift and shock waves parameters relationships in laser plasmas generated on the surfaces of solid targets

Experimental studies of the laser-induced Al plasma expansion during laser pulse into ambient air under pressures of 76 - 760 Torr was performed using 2-channel ADC attached to photomultipliers. Simultaneous measurements of the temporal dynamics of entire plasma emission and neutral Al 396.15 nm emission vs. laser pulse form were carried out with resolution 10 ns. It was detected dualization of a plasma head front, corresponding laser Q-switched pulse. This phenomena may be caused by decay of the laser-supported detonation wave. Distance on which plasma front observed vs. time was obtained under different pump energy of Nd:YAG laser. These results show that plasma expansion dynamics can be described by fast ionization wave model and laser- supported detonation wave model depending on laser pulse form.