A way to produce bursts of gamma-rays on demand that are brighter than the rays produced by radioisotopes, in a device that is smaller and cheaper than conventional sources is reported in Nature Physics this week. The device could improve the use of gamma-ray radiographic screening of shipping containers and enable the greater use of gamma-rays for studying nuclear reactions.
Gamma-rays are a type of electromagnetic radiation that are shorter in wavelength and more deeply penetrating than the X-rays used in medical imaging. Common uses of gamma-rays include cancer therapy, extending food lifetime by killing bacteria, and screening cargo for nuclear materials, arms and explosives. These applications currently rely on gamma-rays emitted from the nuclear decay of radioisotopes such as cobalt-60 and caesium-137.
The device now demonstrated by Dino Jaroszynski and colleagues uses an intense laser to drive a beam of electrons through a plasma and simultaneously excite resonant oscillations of the electrons to produce an intense beam of gamma-rays — much more intense than the radiation produced by radioisotopes. The source is also smaller and cheaper than conventional accelerator-based radiation sources, which could enable the wider use of gamma-rays in scientific research.