Time resolved imaging of nanoscale dynamics of gas phase metal particles

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If macroscopic matter is reduced in size to almost atomic dimensions, many of its properties change dramatically. This is particularly true for structural and electronic properties, and one can therefore expect that also many aspects of motional dynamics will differ substantially from macroscopic behavior. We intend to study how isolated nanoparticles deform or oscillate after a strong excitation. This is presently an almost unexplored field, as no technique was available up to now which couldmonitor the time-dependent shape of a free nanoparticle. We intend to directly image the nanoparticle dynamics for the first time with a novel technique employing time-resolved x-ray diffraction. Ultrashort X-ray pulses from a free electron laser shall be used to measure the time-dependent deformation of the particles after an excitation by a strong optical laser pulse. These „movies“ of the nanoparticle dynamics will not only offer direct access to the elastic properties of the particles and the underlying atomic interactions, but it will also allow one to study how these are changed by a melting of the particles, by a strong electronic excitation, or a high charging. The general atomic structure, the surface morphology as well as the coupling between electrons and nuclei will affect the dynamics. We expect to observe many novel dynamical phenomena which will stimulate research fields far beyond nanophysics.