A photomultiplier tube (PMT) is a highly sensitive device used to detect and amplify light signals. It works by converting incoming photons into electrons, which are then multiplied through a series of dynodes, resulting in a measurable electrical signal. PMTs are commonly used in applications such as nuclear physics, medical imaging, and astronomy. These tubes are known for their ability to detect very low levels of light, making them essential in experiments where precision is crucial. PMTs can respond to a wide range of wavelengths, from ultraviolet to visible light, enhancing their versatility in various scientific fields.