Interaction of slow multicharged ions with surfaces C. Lemell, K. Schiessl, B. Solleder, K. T¨okesi, C.O. Reinhold, and J.Burgd¨orfer Institute for Theoretical Physic/E136 Oak Ridge National Laboratory, Oak Ridge, USA ATOMKI, Debrecen, Hungary During this reporting period we have continued to perform different kinds of simulations on the interaction of charged particles with solid surfaces. For these calculations we have set up simulations codes based on time dependent density functional theory. Using such methods, basic properties of the solid such as, e.g., the density of states are only represented correctly in the model if large systems with large amounts of memory are available. To propagate the wavefunctions in time in a numerically efficient manner we use a second-order split-operator method [1]. These methods require the extensive use of mathematical libraries to solve linear algebra problems as LAPACK or, on RS6000 machines, ESSL. Our codes are highly parallelized and reach up to 85 % prozessor capacity. As one example of our results we present a short account on ion-surface interactions without charge exchange (stopping). In this project we simulated the transport of highly charged ions at large distances from metalic surfaces. As long as a multiply charged ion does not approach the surface to a distance smaller than d c it only dielectrically polarizes the target. For large distances, the induced polarization will accelerate the ion towards the surface (image charge acceleration). If the projectile velocity has a component paral- lel to the surface the induced polarization will lag the projectile and therefore exert an additional retarding force on the ion known as the stopping power. To test models for the calculation of the stopping power it is favorable to measure the energy loss of projectiles that have passed a surface at a close distance but without having undergone any charge transfer reactions. This can be done using metallic microcapillaries. Considering an experimental setup as in [2] it is possible to extract projectiles in a particular charge state to vacuum. Angular deflection and energy loss can be measured for ions in their original charge state. In linear response theory the stopping power S scales as [3] S (Q, b, v)= Q 2 · S (Q =1, b, v)= Q 2 · S (b, v) (1) with b being the distance of a projectile with charge Q moving parallel to the surface. For distances larger than the critical distance d c = √ 2Q/W ,