Abstract
We investigated the spatiotemporal evolution of the expanding femtosecond laser ablation plume of Al with the ultrafast XAFS spectroscopy system that consists of a femtosecond laser plasma source and a Kirkpatrick-Baez (K-B) microscope. We successfully assigned the ejected ablation particles based on the measured absorption spectrum structures near the Ln, llt absorption edge of Al, and clarified the spatial distribution of Al+ions, Al atoms, and liquid Al fine particles in the plume. We also investigated a temperature evolution of the liquid aluminum particles during the expansion of the plume based on an analysis of the slope of the L absorption edge. This suggests that the emitted Al particles travel in a vacuum as a liquid phase with a temperature of about 2500 to 4200 K. These results demonstrate the potential of our system for investigating ultrafast dynamics of femtosecond laser ablatio
