fotomultipliërbuizen

A photomultiplier tube, often abbreviated as PMT, is a highly sensitive detector of light. It works by converting incoming photons into a measurable electrical signal. The process begins when light strikes a photocathode, a thin layer of material that emits electrons when illuminated. These emitted electrons are then accelerated and directed towards a series of electrodes called dynodes. Each dynode is held at a progressively higher positive voltage than the previous one. When an electron strikes a dynode, it causes the emission of several secondary electrons. This cascade effect, where each impact generates more electrons, amplifies the initial signal significantly. Finally, these amplified electrons are collected by an anode, producing a measurable current. The sensitivity of a photomultiplier tube is remarkable, allowing it to detect even single photons. This makes them invaluable in a wide range of scientific and industrial applications. They are commonly used in scientific research for detecting faint light sources, such as in spectroscopy, scintillation counting, and astronomical observations. In medical imaging, they play a role in PET scanners. Industrially, they can be found in applications requiring precise light detection, like in high-speed color sorting or quality control processes. The vacuum environment within the tube is crucial to prevent collisions between electrons and air molecules, which would hinder the amplification process.