Tunable gamma ray source

摘要

A source of gamma rays (a photon beam) at a single energy produced by the single-quantum annihilation of accelerated positrons with electrons of a target element. The photons are emitted predominantly in the forward direction and are accompanied by background radiation which can be differentially suppressed. The energy of the photons is determined by varying the energy of incident positrons. The photon beam is usable in materials research and analysis, medical diagnosis and therapy, and numerous other fields.