Influence of laser irradiance and helium ambient on the expansion of laser-produced carbon plasma

The emission features of laser ablated carbon plasma plume generated in helium ambient have been investigated with time resolved plasma diagnostic technique. At lower irradiance levels only a slowly propagating C2 component is seen. At higher irradiance levels, emission from C2 shows a twin peak distribution in time. The present results also show that the helium ambient pressure and laser irradiance has opposite effects on the time of flight profiles of C2 species. A simple adiabatic expansion model appears to provide a good description of the plume range and this may provide useful for scaling deposition experiments in terms of pressure and laser irradiance.