Fotopowielacz

Fotopowielacz, also known as a photomultiplier tube or PMT, is a highly sensitive vacuum tube that detects and amplifies light. It converts photons into an electrical signal. The process begins when light strikes a photocathode, a light-sensitive material, which then emits electrons. These electrons are accelerated towards a series of electrodes called dynodes. Each dynode is at a successively higher electrical potential. When an electron strikes a dynode, it causes the emission of several more electrons, a process called secondary emission. This cascade of electrons is amplified at each dynode stage, resulting in a significant multiplication of the original signal. The amplified electron current is then collected by an anode, producing a measurable electrical output.

Fotopowielacze are renowned for their exceptional sensitivity, capable of detecting even single photons. They also offer very fast response times, making them suitable for applications requiring precise timing. Their broad spectral response allows detection of light across a wide range of wavelengths, from ultraviolet to near-infrared, depending on the photocathode material used. The main components of a fotopowielacz include a vacuum-sealed glass envelope, a photocathode, a series of dynodes, and an anode. They are typically operated at high voltages to achieve the necessary acceleration and amplification.

Due to their sensitivity and speed, fotopowielacze find applications in various scientific and industrial fields. These include particle physics experiments for detecting Cherenkov radiation, medical imaging techniques like PET scans and gamma cameras, astronomical observations for detecting faint celestial objects, and industrial quality control for inspecting materials and components. Their ability to detect low light levels and provide rapid measurements makes them indispensable tools in many advanced technologies.