A Spectroscopic Analysis Study of Graphite Using Laser Technique

Results of single and double pulses (SP- and DP) Q-switch Nd:YAG laser induced breakdown spectroscopy (LIBS) at atmospheric pressure on the structure of graphite target are reported. Various parameters, such as laser energy, placement of the focus with respect to the surface of illumination, and time delay between laser pulse and ICCD camera pulse were used as variables. This study contributes to a better understanding of the LIBS plasma dynamics of the SP- and DP effect by observing the temporal evolution of emission line of graphite. The gate width and the delay time were adjusted to achieve the best possible signal to noise ratio. Electron densities were found from Stark broadening. The temporal behavior of the last one was also estimated. It was found that the electron density for DP of 2 x 20 mJ is higher than that for SP of 40 mJ of the same total energy. The results show a faster decay of continuum, spectral lines, and a shorter plasma life.