Based on the 511 keV photons produced by electron-positron annihilation, compute or explain the photon energy (electron rest mass 0.511 MeV). For PET imaging and annihilation demos.
电子对湮灭产生两个 511 keV 光子。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Annihilation energy | E = 2mₑc² = 1.022 MeV | Dirac 1930 |
| Electron rest mass | mₑc² = 0.511 MeV | CODATA 2018 |
| Two-photon | Back-to-back 511 keV photons | PET physics |
| Momentum conservation | Photons emitted at 180° | Conservation laws |
| PET application | Coincidence detection localises | PET imaging |
| Three-photon | Positronium triplet branch | Positron physics |