FELs of Europe Whitebook

The present Whitebook is a common document of the FELs of Europe consortium. It presents a science case for the ensemble of European Free Electron Laser (FEL) facilities as a whole, illustrating by selected examples the scientific progress achieved so far and providing an excellent basis for future developments. The Whitebook also addresses the major challenges that must be met in order to exploit the revolutionary potential of this new technology. Moreover, it proposes specific steps towards enhancement and firm establishment of the collaboration of all FEL facilities in Europe, to the benefit of science and innovation.