When energetic particles impinge on solid surfaces, a multitude of phenomena is observed. Among them are erosion of material (i.e. sputtering), surface modifications, reflection or implantation of projectiles, emission of electrons and photons, and other secondary particles, etc. On the one hand the observed phenomena are of basic interest with respect to questions from fundamental research. On the other they are also relevant for a multitude of applications such as semi-conductor industry, for surface analysis tools and for fusion research, as they largely contribute to the interaction of the fusion plasma with the walls of the surrounding vacuum vessel. The international thermonuclear experimental fusion reactor ITER is currently under construction in the south of France. Its aim is to demonstrate the feasibility of using nuclear fusion as a safe and eco-friendly source for energy production. The interaction of the hot fusion plasma with the vacuum vessel walls in fact constitutes one of the major challenges in the successful realization of the ITER project. In this work, various aspects of plasma wall interaction issues relevant for future fusion devices are studied under controlled laboratory conditions mainly using a highly sensitive quartz crystal microbalance technique. A special emphasis is put on investigating the evolution of plasma facing materials under energetic particle impact of species, that will be present in the fusion machine. Experimental investigations are complimented by a thorough modeling of the observed processes. By this a unique insight into the dynamics of material mixing and particle retention, as well as basic mechanisms of erosion phenomena can be gained. Within the framework of this thesis, all of the three materials, which were originally envisaged as plasma facing components in ITER are investigated, i.e. carbon, tungsten and beryllium. The projectiles used in the studies range from fueling species such as deuterium to impurity ions such as nitrogen, argon and neon. In the second part of this thesis, detailed investigations on the emission of electrons from solid surfaces upon impact of highly charged ions will be presented. The studies aim at a more profound insight into the influence of the electronic structure of the target material on the neutralization and de-excitation of a highly charged ion in front, at and below the surface. An almost continuous variation of the surface properties is realized by depositing single layers of C60 films on a clean gold substrate, in combination with studies on clean gold and a bulk carbon surface (HOPG). In order to assess and better understand the individual contributions of electron emitting processes, total electron emission yields are determined for a wide range of projectile charge states and impact energies.