"X-ray crystallography yields atomic-resolution 3D images of the whole spectrum of molecules ranging from small inorganic clusters to large protein complexes constituting the macromolecular machinery of life. Life is not static, and many of the most important reactions in chemistry and biology are light induced and occur on ultrafast timescales. These have been studied with high time resolution primarily by ultrafast laser spectroscopy, but they reduce the vast complexity of the process to a few reaction coordinates. Here we develop attosecond serial crystallography and spectroscopy, to give a full description of ultrafast processes atomically resolved in real space and on the electronic energy landscape, from co-measurement of X-ray and optical spectra, and X-ray diffraction. This technique will revolutionize our understanding of structure and function at the atomic and molecular level and thereby unravel fundamental processes in chemistry and biology. We apply a fully coherent attosecond X-ray source based on coherent inverse Compton scattering off a free-electron crystal, developed in this project, to outrun radiation damage effects due to the necessary high X-ray irradiance required to acquire diffraction signals [A. Cho, ""Breakthrough of the year"", Science 388, 1530 (2012)]. Our synergistic project will optimize the entire instrumentation towards fundamental measurements of the mechanism of light absorption and excitation energy transfer. The multidisciplinary team optimizes X-ray pulse parameters, in tandem with sample delivery, crystal size, and advanced X-ray detectors. We will apply our new capabilities to one of the most important problems in structural biology, which is to elucidate the dynamics of light reactions, electron transfer and protein structure in photosynthesis. Also, the attosecond source can provide a coherent seed and will help to overcome peak flux limitations of X-ray FELs by introducing chirped pulse amplification to FEL technology."
- NaturwissenschaftenGeowissenschaften und verwandte UmweltwissenschaftenGeologieMineralogieKristallographie
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