| Abstract | Experiments performed at the FLASH soft x-ray free electron laser in Hamburg over the past three years have produced significant new results in biomolecular imaging, high-energy density science, and ultra-fast structural sciences. The results have direct relevance to planned experiments at LCLS. Numerous models have been developed to describe photon-material interactions under extreme conditions. Our models proved to be successful in designing and interpreting experiments at FLASH, and produced accurate predictions. LCLS will deliver pulses of much shorter wavelength and of higher photon intensities than FLASH, and may enable ultrafast coherent diffraction imaging of isolated molecules. In this presentation I will describe recent theoretical and experimental results, and I will discuss some of the new challenges and opportunities awaiting us at LCLS. |