How is the energy of ionizing radiation measured?

The energy of ionizing radiation is measured in electron volts (eV) because this unit specifically quantifies the amount of energy gained or lost by an electron when it moves through an electrical potential difference of one volt. This measurement is highly relevant in the context of atomic and subatomic particles, making it particularly suitable for describing various types of radiation, such as X-rays or gamma rays, which are crucial in both radiation protection and medical imaging.

Electron volts provide a practical scale for discussing the energies typically involved in ionization processes, as they are equivalent to very small amounts of energy, which is ideal for measuring the interactions of photons and high-energy particles with matter. Other units, such as joules, could also describe energy but are less commonly used in this specific context because the values might be larger and less intuitive for the types of energies involved in particle physics.

Watts measure power (energy per unit time), while amperes measure electric current, neither of which directly relate to the energy measurement of individual radiation particles. Thus, electron volts stand out as the most appropriate and commonly used unit in the field of radiation.