Measurement and Interpretation of Spontaneous Line Emission from a Common Upper Level in Laser-Produced Carbon Plasmas

The quenching of spontaneous-emission coefficients recently inferred at Princeton from measured intensity ratios of visible and extreme-ultraviolet lines from a common upper level in laser blowoff plasmas is further investigated using a ruby laser. The line intensity ratios of the Civ 3s-3p and 2s-3p transitions, for similar laser targets, show a similar dependence on separation from the target as the previous experiments. Both of these results can, however, be interpreted in terms of density gradients and Stark broadening wihtout invoking changes in Einstein A values.