Spectroscopy of laser-induced carbon plasma with nanosecond time resolution

Abstract

Emission spectra in the visible spectral range generated by a Nd:YAG laser shining on graphite targets were taken with time-averaging and time resolution. The analyses of the components and temperature of the plasma components were performed in helium environment using the LIBS (Laser Induced Breakdown Spectroscopy) technique. The vibration-rotation temperature of the C₂ radical in the plasma initiates around 8000 K and drops exponentially with time. The rate coefficient of the exponential emission decay is 0.0018 ns^-1. Thus, the expected lifetime of the C₂2 Swan emission under our experimental conditions is 555 ns. In addition to C₂2, singly and doubly ionized carbon, and in the first phase of the plasma, a continuum electron radiation was also observed.