X-ray Optics Research for Linac Coherent Light Source: Interaction of Ultra-short X-ray Pulses with Matter

Free electron lasers operating in the 0.1 to 1.5 nm wavelength range have been proposed for the Stanford Linear Accelerator Center (USA) and DESY (Germany). The unprecedented brightness and associated fluence predicted for pulses <300 fs pose new challenges for optical components. A criterion for optical component design is required, implying an understanding of x‐ray ‐ matter interactions at these extreme conditions. In our experimental effort, the extreme conditions are simulated by currently available sources ranging from optical lasers, through x‐ray lasers (at 14.7 nm) down to K‐alpha sources (∼0.15 nm). In this paper we present an overview of our research program, including (a) Results from the experimental campaign at a short pulse (100 fs ‐ 5 ps) power laser at 800 nm, (b) K‐α experiments, and (c) Computer modeling and experimental project using a tabletop high brightness ps x‐ray laser at the Lawrence Livermore National Laboratory.