Short-pulse lasers and electron dynamics in warm dense matter

We describe new ideas and tools for analysis of ultra-short pulse laser experiments on warm dense matter. The tools include hydrodynamic codes and a new equation of state for expanded matter. The ion density of excited states, G(j)(E), is used to rapidly evaluate the partition function for many-electron ions which have many excited states. We describe a strategy for determining the dielectric function of expanding warm dense plasmas by analysis of laser experiments. Special attention is given to the remarkable fact that the observed dielectric functions imply an inhibition of free-electron ("Drude") conductivity, which suggests electron localization or a metal-insulator transition. We give preliminary models for experiments on Sri and Au targets. (C) 2005 Published by Elsevier Ltd.