A scintillation detector operates by converting incoming radiation into light, which is subsequently detected and quantified.

These detectors are widely employed in nuclear physics and medical imaging for the detection of ionizing radiation. The core component of a scintillation detector is the scintillator material, which is usually either a crystal or a plastic that emits light upon interaction with radiation. When radiation penetrates the scintillator, it excites the atoms within the material, leading to the emission of photons. These emitted photons are then captured by a photomultiplier tube, which transforms the light into an electrical signal that can be measured.

The photomultiplier tube is a vacuum tube that incorporates a series of electrodes known as dynodes. When a photon hits the first dynode, it releases multiple electrons, which are subsequently accelerated toward the next dynode. This process is repeated through each dynode, with each stage producing more electrons than the one before, ultimately resulting in a significant amplification of electrons collected at the final dynode. The electrical signal generated is proportional to the number of photons detected, which correlates directly with the amount of radiation that interacted with the scintillator.

Scintillation detectors are known for their high sensitivity, enabling them to detect very low levels of radiation. They also operate rapidly, allowing for real-time radiation detection. However, they are not ideal for detecting high-energy radiation, such as gamma rays, as this type of radiation can penetrate the scintillator and evade detection. In such instances, alternative detection methods, such as Geiger-Muller counters, may be employed.