penetration

Particle radiation penetration refers to how far different types of radiation can travel through matter. This depends on the particle's type, energy, and the material it encounters.1

Charged particles, like alpha particles (two protons, two neutrons) and beta particles (electrons), interact continuously with matter through the Coulomb force. They lose energy by ionizing or exciting atoms, slowing down as they travel. Alpha particles, being much heavier than electrons, travel in straighter paths, while electrons are deflected more erratically.21

Uncharged radiation, such as gamma rays and neutrons, interact less frequently. They must first undergo a significant interaction to produce charged particles, which can then be detected. Gamma rays, being electromagnetic photons, can travel considerable distances before interacting, with their penetration power stemming from their lack of electric charge. The mean free path, or average distance between interactions, varies greatly depending on the radiation's energy and the material's properties.34