Time Resolved Analysis of C₂Emission from Laser Induced Graphite Plasma in Helium Atmosphere

Abstract

We report time resolved study of C 2 emission from laser produced carbon plasma in presence of ambient helium gas. The 1.06 µm radiation from a Nd:YAG laser was focused onto a graphite target where it produced a transient plasma. We observed double peak structure in the time profile of C 2 species. The twin peaks were observed only after a threshold laser fluence. It is proposed that the faster velocity component in the temporal profiles originates mainly due to recombination processes. The laser fluence and ambient gas dependence of the double peak intensity distribution is also reported.