Cherenkov radiation

Cherenkov radiation refers to a physical phenomenon that can be observed e.g. in the cooling water around spent fuel assemblies as bluish light. The phenomenon occurs when charged particles in a translucent medium - for example water or glass - move faster than the light in the medium.

Cherenkov radiation is used in nuclear and (astro)particle physics to detect high-energy charged particles and measure their speed. Applications are also known in the medical field, for example in imaging. The phenomenon was named after its discoverer, the Soviet physicist Pavel Cherenkov.