Organized by the Institute of Experimental Physics, University of Bialystok and the Institute of Atomic Energy, Swierk under the auspices of the European Crystallographic Association; Committee of Crystallography, the Polish Academy of Sciences; and the Polish Neutron Scattering Society The School is financially supported in part by the International Union of Crystallography; the European Crystallographic Association; the European Office of Aerospace Research & Development; the Ministry of Science and Information Society Technologies; the Warsaw University of Technology; and the University of Bialystok.
		Materials science and surface modifications studied with the new X-ray free-electron lasers Ingolf Lindau Stanford University and Lund University, Sweden Topics Efforts are now under way to develop radiation sources that combine the unique properties of lasers (e.g. high peak brilliance, full coherence, femtosecond time-structure) and synchrotron radiation (e.g. high average brilliance, full wavelength tunability and variable polarization into the hard x-ray regime). In these lectures we will survey the ongoing projects worldwide for fourth generation light sources based on accelerators and briefly describe the different technological approaches: SASE (self-amplified spontaneous emission)- based linacs, energy recovery linacs and seeded linacs (high gain harmonic generation). The motivation for these source developments is the novel scientific opportunities and in these lectures we will focus on topics in materials science and surface modifications. We will start by reviewing the first results obtained recently on laser ablation and cluster fragmentation using SASE-radiation at a wavelength of about 100 nm at the TESLA TEST FACILITY I in Hamburg. Then we will summarize recent surface melting experiments at the Sub-Picosecond Pulse Source (SPPS) at Stanford University. The latter experiments were performed with 100 femtosecond 9 keV x-rays of incoherent radiation. These two examples will serve as an introduction to the science that can be anticipated when the Linac Coherent Light Source (LCLS), now under construction at Stanford gets into operation for users in 2008 (advanced plans are in place for a similar source in Hamburg with anticipating operation in 2012). LCLS is based on the SASE-concept for the spectral region 1.5-0.5 nm. The unprecedented characteristics of this source (peak brilliance ten orders of magnitude above existing synchrotron radiation sources, femtosecond pulse-structure, full transverse coherence) will open up a number of new research areas. The femtosecond time-structure (down to 1-2 femtosecond) will make it possible to study structural dynamics on a time-scale relevant for lattice vibrations and breaking/forming chemical bonds. With the high intensity of the x-ray pulse the structure of non-crystalline materials can be determined and the time-evolution of various phenomena can be imaged. The LCLS can further be used to study surface ablation phenomena on the femtosecond time-scale and can also be applied to create and probe warm dense matter, a state of matter of great importance in for instance laser annealing (in addition to the fields of plasma production, inertial fusion and astrophysics). The LCLS radiation can also be used to study a range of phenomena in condensed and soft matter physics over broad length/time scales, for instance problems in nanoscale dynamics related to structural relaxation in polymers, structural phase transitions and domain switching in magnetic materials. Finally we will address briefly the technological challenges that have to be overcome to realize the novel science described above.