Spectroscopic studies of magnesium plasma produced by fundamental and second harmonics of Nd:YAG laser.

In the present experimental work, laser induced magnesium plasma has been characterized using plasma parameters. The plasma has been generated by the fundamental (1064 nm) and second harmonics (532nm) of Nd:YAG laser. The plasma parameters such as electron temperature and electron number density have been extracted using Boltzmann plot method and Stark broadened line profile, respectively. The laser irradiance dependence and spatial behavior of electron temperature and number density in laser induced magnesium plasma have been studied. The electron temperature as a function of laser irradiance (0.5 to 6.5GW/cm2) ranges from (9.16-10.37)×10³K and (8.5-10.1) ×10³K, and electron number density from (0.99-1.08)×1016cm-3 and (1.04-1.22)×1016cm-3 for 1064 and 532 nm, respectively. These parameters exhibit fast increase at low laser irradiance and slow increase at high irradiance. The spatial distribution of electron temperature and electron number density shows same decreasing trend up to 2.25mm from the target surface. The electron temperature and number density decrease from (9.5-8.6)×10³K, (1.27-1.15)×1016cm-3 and (10.56-8.85) ×10³K, (1.08-0.99)×1016cm-3 for 532nm and 1064 nm laser ablation wavelengths, respectively. [ABSTRACT FROM AUTHOR]