Final answer:
Scintillators, which include materials such as phosphors, emit light when hit by X-rays or gamma rays. This process is used in various applications to detect and analyze radiation by converting its energy into visible light.
Step-by-step explanation:
Materials that give off light when struck by X-rays or gamma rays, causing them to fluoresce, are known as scintillators. This process is a result of the radiation energy exciting the atoms within a material, such as a phosphor, leading to the emission of light. Scintillation occurs when the absorbed energy from the radiation excites electrons to a higher energy state. These electrons then fall back down to their ground state, releasing energy in the form of light. Fluorescent materials, including certain dyes and phosphorescent substances, can absorb energy from various forms of radiation and then re-emit this energy as visible light. This principle is utilized in multiple applications, such as medical imaging, radiation detection, and astrophysical research.