Time-dependent neutralization of highly charged ions

When we remove electrons from an atom, it becomes a charged ion. By removing more and more electrons, the ion can reach a very high state of charge. When this highly charged ion approaches the surface of a material, there are many phenomena occurring at once. The ion can directly hit atoms, leading to billard-like motion of the surface atoms. More importantly, because it tries to minimise its charge, the ion will start to extract electrons from the materials surface. This electron capture affects the atoms motion in interesting ways, transferring a large amount of energy to the surface. This may lead to permanent changes in the surface structure, which can be useful for applications later on. While this is a nice qualitative picture, we do not have a quantitative and deep understanding of highly charged ions impacting on a surface. The reason is the coupling of all processes with one another, which makes this a truly complicated problem to clarify in detail. Our project will push forward what has been achieved in the laboratory using highly charged ions as well as what is possible in large-scale computer simulations of such ions, in close collaboration between theory and experiment. Utilizing thousands of computer processors simultaneously and developing new computer programs allows us to simulate ion impacts. Upon completion, we will be able to translate experiments to the computer and closely observe their details before turning to specific applications.