Influence of air pressure on mechanical effect of laser plasma shock wave

The influence of air pressure on mechanical effect of laser plasmashock wave in a vacuum chamber produced by a Nd:YAG laser has beenstudied. The laser pulses with pulse width of 10ns and pulse energyof about 320mJ at 1.06$mu $m wavelength is focused on the aluminiumtarget mounted on a ballistic pendulum, and the air pressure in thechamber changes from $2.8times 10^{3}$ to 1.01$times $10$^{5 }$Pa. The experimental resultsshow that the impulse coupling coefficient changes as the airpressure and the distance of the target from focus change. Themechanical effects of the plasma shock wave on the target areanalysed at different distances from focus and the air pressure.