Plasma properties of nano-second laser ablated iron target in air

Abstract

In the present work, we studied the optical emission spectra of iron (Fe) plasma produced by the fundamental (1064 nm) and second (532 nm) wavelengths of an Nd: YAG laser. The plasma emission has been recorded spatially using five spectrometers covering the spectral region from 200 to 720 nm. The laser beam was focused on target material by placing it in air at atmospheric pressure. The experimentally observed line profiles of neutral iron (Fe I) have been used to extract the electron temperature using the Boltzmann plot method, whereas, the electron number density has been determined from the Stark broadening. The electron temperature is calculated by varying distance from the target surface along the line of propagation of plasma plume and also by varying the laser irradiance. Besides we have studied the variation of number density as a function of laser irradiance as well as its variation with distance from the target surface. It is observed that electron temperature and electron number density increases as laser irradiance is increased. Key words: Iron, laser ablation, optical emission spectroscopy, electron temperature, electron number density.