With the advent of the first x-ray lasers world-wide, this workshop aims at bringing together   scientists from all disciplines interested in exploring the revolutionary capabilities of these new sources, which will provide fully coherent, femtosecond short x-ray pulses of exceptional brightness. For instance, with accelerator-based free electron lasers (FEL) about ten orders of magnitude will be gained on peak brightness with respect to today's synchrotron radiation storage rings. Therefore, one may expect a spectacular development of the entire field of x-ray science, comparable to the revolution of optical science due to the advent of femtosecond lasers. The future x-ray lasers will thus bridge a gap by extending the performance of optical lasers to the x-ray photon energies and the workshop aims at bringing together these two communities.

Linear accelerator-based SASE and seeded FEL sources are today the most mature instruments for achieving the above ultimate performance. A suite of next generation x-ray sources has been proposed by the ARC-EN-CIEL project, which predicted performance can be taken as a benchmark for a future x-ray source., Besides, laser-plasma based electron accelerators become possible today and will offer alternative schemes. All these sources will have their own characteristic strength and be most suitable for one particular photon energy range or a specific type of application. The interested users are therefore invited to express their scientific visions and needs. Together we aim at identifying key experiments that will redefine the technical requirements and thus determine priorities for the performances of a future x-ray light source in France.

All participants are encouraged to contribute to the workshop program. Overviews about experiments already performed at or planed for existing or future x-ray lasers will be given by invited speakers. These presentations will introduce specific scientific fields or experimental techniques and will be followed by contributed talks chosen from the submitted abstracts. One session will be dedicated to parallel working groups, which aim at the formation of teams with a common experimental interest. This process is also envisioned to stimulate new experiments at existing or currently developed x-ray laser sources.