Inthepastfewdecades,greatprogresshasbeenmadeinthe?eldofdynamical interactions of photons and charged particles with surfaces. Developments in this ?eld have largely been driven by technological advances. Foremost, the preparation and characterization of atomically ?at surfaces has opened up opportunities to precisely and reproducibly investigate surface structure and dynamics in unprecedented detail. An equally important advance represents the availability of new sources for projectiles interacting with and probing surfaces. Third-generation s- chrotron sources provide high-brilliance photon ?ux over a broad range of energies extending from the ultraviolet to the hard X-ray regime. In the c- text of the primary topics of this book of even greater importance is the development of ion sources that provide slow, very highly charged ions with signi?cant intensities covering charge states up to bare uranium. Currently pursueddevelopment projects suchas HITRAP(highly charged trapped ions) atGSIDarmstadtholdthepromisetodeliverwithinthenextfewyearscooled highly charged ions in the sub-eV kinetic energy regime. These advances in experimental techniques have led to an increased - cus on technological applications. Prominent examples include the controlled nanostructuring of surfaces for novel functionalities on the sub-micron scale and the search of surface materials suited for divertor surfaces in future th- monuclear fusion reactors, in particular to control and reduce physical and chemical sputtering. Concurrently, theory has made great strides. The und- standing and solution of the many-body problem beyond the ground state, which is at the core of the description of dynamical surface processes, has considerably advanced.
