The bombardment of solid surfaces by fast neutral or ionized particles has been of interest for more than 100 years. This interest stems from the many important applications that depend on these processes. For example, electron emission initiated by particle impact on a converter surface permits detection of very small particle currents or even single-particle counting for highly sensitive mass spectrometry. Sputtering, that is, the removal of atomic constituents from a solid because of particle impact, is highly important in many fields, including space flight, thermonuclear fusion research, and semiconductor technology. Radiation damage in solids, which is caused by the impact of energetic particles, can, for example, be utilized in light-ion radiotherapy for the destruction of cancerous tissue.