Certified Safety Professional Practice Exam

Direct ionization occurs when charged particles, such as alpha or beta particles, interact with matter and transfer energy to the atoms in the material. This interaction can lead to the ejection of electrons from the atoms, resulting in the formation of ions. Since they are charged, these particles can produce ionization more efficiently as they pass through the medium, primarily through collisions with other atoms.

In contrast, indirect ionization typically involves neutral particles, such as photons, which predominantly interact with matter by producing secondary charged particles rather than directly causing ionization. Electromagnetic ionization isn't a recognized term in the context of particle interactions with matter, as electromagnetic processes generally refer to the behavior of photons rather than their direct capability to ionize materials. While "particle ionization" might sound plausible, it does not specify the mechanism and isn't a recognized category like direct or indirect ionization. Therefore, the specific term that accurately describes the ionization that results from charged particle interactions is direct ionization.