Fundamental Processes in the "Tender" X-Ray Region (2-10 keV)
Abstract: We have stimulated a revival of scientific interest in processes following absorption of a tender X-ray photon by an isolated atom or molecule. This interest is enabled by recent instrumentation developments that allow one to follow ultrafast processes on the subfemtosecond timescale. We have developed a hard X-ray photoelectron spectrometer, a reaction microscope, and an X-ray spectrometer dedicated to this purpose. I will concentrate my talk on the recoil effects that occur after the ejection of a fast photoelectron, localization/delocalization of a deep core hole, double core hole spectroscopy, and the ultrafast fragmentation that occurs after deep inner shell excitation.