SASE based 4th generation light sources and the LCLS project

Advances in the physics and technology of photoinjectors, linear accelerators, insertion devices and free-electron lasers make it now possible to generate coherent radiation in the X-ray region by means of the Self-Amplified-Spontaneous-Emission (SASE) process. This radiation has much higher brightness, shorter pulses and coherence than present 3 ^rd generation sources. The status of the physics and technology involved in a radiation source based on SASE is reviewed, together with an overview of the main activities in this field around the world. The design status of a 1.5 Å SASE-FEL at SLAC, called the Linac Coherent Light Source (LCLS), is described