The development of next generation laser plasma sources for novel applications in various fields ranging from astro-physics, fusion research to particle acceleration and tumor therapy requires methods to study the plasma dynamics and heating on short spatial (few nanometers) and temporal scales (few femtoseconds). Free electron lasers are identified as a potential new tool to achieve this goal for various plasma properties since they combine short bunches, high photon numbers with small bandwidth and high penetration power even through several microns of solid density plasmas.
We give an overview over recent advances in theory and experiments for transferring established scattering techniques into the short-pulse laser domain. Besides the future potentials of the small angle scattering technique we will focus on the possible impact of resonant scattering on the understanding and advancement of laser-based particle sources. The simultaneous measurement of structure and opacity with a single method, with nanometer and femtosecond resolution would enable a level of understanding both in plasma physics as well as transient, non-equilibrium atomic physics that could help developing better predictive simulation capabilities as well as new solutions to defiances towards optimized laser particle source