Molecular species formation in laser-produced plasma

Abstract

Laser-induced breakdown spectroscopy (LIBS) utilized laser-induced transient plasma (LIP) as a sampling and emission source, which is formed by focusing intense laser pulses having irradiance higher than the ablation or plasma formation threshold of the substance. Molecular LIBS provides information about the sample composition by identifying the molecular emission lines, usually observable at the later stages of the plasma formation since molecular formation occurs mainly due to the recombination effect as the plasma cools down. This chapter provides a brief description of molecular species formation in LIP through time-resolved optical emission spectroscopy. It discusses the nanosecond and femtosecond laser light induced CN and C 2 formation and their evolution dynamics from two carbon-bearing materials. The chapter highlights the carbon atomic and ionic emission dynamics from a graphite sample at different N 2 gas background pressure.