Spatial distribution of carbon species in laser ablation of graphite target

We report on the temporal evolution and spatial distribution Of C-2 and C-3 molecules produced by KrF laser ablation of a graphite target using laser induced fluorescence imaging and optical emission spectroscopy. Spatial den sity profiles Of C-2 were measured using two-dimensional fluorescence in va rious pressures of different ambient (vacuum, nitrogen, oxygen, hydrogen, h elium, and argon) gases at various ablation laser fluences and ablation are a. A large yield Of C-2 is observed in the central part of the plume and ne ar the target surface and its density and distribution was affected by the laser fluence and ambient gas. Fluorescent C-3 was studied in Ar gas and th e yield Of C-3 is enhanced at higher gas pressure and longer delay times af ter ablation. (C) 2001 American Vacuum Society.