Line shape study of Ba ions in laser produced plasmas

Detailed measurements of spatio-temporal variations in the line strengths and line shapes for Ba ion absorption lines, observed in laser-ablated YBCO plasma plumes, show that the presence of ambient oxygen leads to enhanced local number densities and temperatures at the expanding front of the plasma plume. Enhanced local temperatures (and local excitation rates) are attributed to the increased collisional redistribution of high initial z-directed plume velocities in the presence of ambient oxygen.