Szintillatoren

Szintillatoren, or scintillators, are materials that emit light when traversed by ionizing radiation. The emitted photons, typically in the visible or near-ultraviolet range, are detected by photodetectors to infer properties such as the energy and timing of the incident radiation.

They come in two broad classes: inorganic crystalline scintillators and organic scintillators. Inorganic crystals such as NaI(Tl), CsI(Tl), BGO, and LSO/LYSO generally offer higher light yields and good energy resolution, but vary in decay time and hygroscopicity. Organic scintillators, including plastic and liquid types, tend to be faster and mechanically robust but may have lower density and light yield. Some materials, like NaI(Tl), are hygroscopic and require encapsulation.

The scintillation mechanism involves excitation of luminescent centers doped into the material, followed by photon emission with characteristic decay times. The light yield is expressed as photons per MeV of deposited energy and depends on dopant concentration, temperature, and crystal quality. Emission spectra are material-specific, which influences the choice of photodetectors.

Light produced in the scintillator is collected by photodetectors such as photomultiplier tubes or silicon photomultipliers, often with optical coupling and light guides. Detector performance is governed by the light yield, transparency (attenuation length), decay time, and the photosensor’s quantum efficiency, as well as the geometry of the scintillator and shielding.

Applications include gamma-ray spectroscopy, medical imaging (PET and SPECT), high-energy physics experiments, homeland security, and dosimetry. Scintillators are selected to balance speed, resolution, and efficiency, and are frequently used with complementary systems to optimize overall detector performance.