annihilatsioonifotoneid
Annihilatsioonifotoneid, also known as annihilation photons, are gamma-ray photons produced during the process of particle-antiparticle annihilation. When a particle, such as an electron, encounters its corresponding antiparticle, like a positron, they annihilate each other, converting their entire mass into energy. This energy is typically released in the form of two or more photons. The most common and well-studied example is electron-positron annihilation, which predominantly produces two photons. These photons are emitted in opposite directions to conserve momentum, and each photon carries half of the total rest mass energy of the electron-positron pair. For an electron and positron at rest, this energy is approximately 511 keV, corresponding to a photon wavelength of about 2.43 picometers. The detection of these characteristic annihilation photons is a significant tool in various scientific fields. In astrophysics, they provide evidence for the presence of antimatter in cosmic environments. In medical imaging, Positron Emission Tomography (PET) scans utilize the detection of annihilation photons to image biological processes. Materials science also employs annihilation photon spectroscopy to study the electronic structure and defects within materials. The precise energy and angular distribution of annihilation photons can reveal information about the initial state of the annihilating particles and the surrounding environment.