Fotomuuntimet

Fotomuuntimet is a term of Finnish origin that translates to "photo multipliers" or "light multipliers". In scientific and technical contexts, it refers to photomultiplier tubes (PMTs). Photomultiplier tubes are highly sensitive detectors of light. They are vacuum tubes that convert incoming photons into a measurable electrical signal. This conversion process involves a photocathode, which emits electrons when struck by photons, and a series of dynodes, which amplify the electron stream through secondary emission. The amplified electron pulse is then collected by an anode, producing a larger current that can be detected and measured.

The extreme sensitivity of photomultiplier tubes makes them invaluable in various scientific disciplines. They are used in fields such as particle physics, nuclear physics, astronomy, and medical imaging. In particle physics, PMTs are employed to detect Cherenkov radiation, which is emitted when charged particles travel faster than the speed of light in a medium. In astronomy, they can detect faint light from distant stars and galaxies. Medical applications include their use in positron emission tomography (PET) scanners and scintillation counters for detecting gamma rays. The ability of PMTs to detect single photons or very low light levels is their most significant characteristic.