Which types of radiation are classified as directly ionizing?

Directly ionizing radiation is characterized by its ability to interact with matter and cause ionization directly through collisions with atoms. Among the types of radiation, alpha particles and beta particles fall into this category.

Alpha particles are heavy, positively charged particles composed of two protons and two neutrons, making them significantly more massive than other radiation types. When alpha particles pass through matter, they quickly lose energy through interactions with electrons, leading to direct ionization of atoms along their path.

Beta particles, which are high-energy, high-speed electrons (or positrons) emitted by certain types of radioactive decay, also directly ionize atoms. They have sufficient energy to cause ionization as they collide with electrons in the atoms of the surrounding material.

In contrast, gamma rays and X-rays, while they do contribute to ionization, do so primarily through interactions with the atomic nucleus or by producing secondary charged particles, making them indirectly ionizing. Neutrons, being neutral particles, do not cause ionization directly and instead must interact with the nucleus to lead to secondary radiation phenomena.

This understanding of directly ionizing radiation is essential for radiation safety as it influences how radiation protection measures are designed and implemented. Knowing that alpha and beta particles are directly ionizing helps professionals assess