Scintillation crystals are materials that emit light when they absorb high-energy radiation, such as gamma rays or X-rays. This property makes them useful in various applications, including radiation detection and medical imaging. When radiation interacts with the crystal, it excites the atoms, causing them to release energy in the form of visible light. These crystals are often used in devices called scintillation detectors, which convert the light into electrical signals for analysis. Common types of scintillation crystals include sodium iodide (NaI) and cesium iodide (CsI). Their efficiency and speed in detecting radiation make them valuable in fields like nuclear medicine and particle physics.