Fluorescence Measurements Of Expanding Strongly Coupled Neutral Plasmas

Abstract

We report new detailed density profile measurements in expanding strongly coupled neutral calcium plasmas. Using laser-induced fluorescence techniques, we determine plasma densities in the range of ${10}^5$ to ${10}^9{\mathrm{cm}}^{-3}$ with a time resolution limit as small as 7 ns. Strong coupling in the plasma ions is inferred directly from the fluorescence signals. Evidence for strong coupling at late times is presented, confirming a recent theoretical result.