Artificial Radioactivity

Artificial radioactivity is the phenomenon by which even light elements are made radioactive by artificial or induced methods.

Artificial radioactivity occurs when a previously stable material has been made radioactive by exposure to specific radiation. Most radioactivity does not induce other material to become radioactive.

Methods of producing artificial radioactive isotopes

Methods of inducing radioactivity

1. Nuclear activation: Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The process of neutron capture, even after any intermediate decay, often results in the formation of an unstable activation product.
2. Photonuclear reactions: A photonuclear reaction is a reaction resulting from an interaction between a photon and a nucleus. During a photonuclear reaction energy of a gamma ray photon is fully or partially absorbed by the nucleus forcing it into and excited state. Most commonly, it will emit a photon, but also a neutron (n), a proton (p) or an alpha (α) particle can be emitted.

Applications of artificial radioactivity

1. Radiation safety: For physicians and radiation safety officers, activation of sodium in the human body to sodium-24, and phosphorus to phosphorus-32, can give a good immediate estimate of acute accidental neutron exposure.
2. Neutron detection: One way to demonstrate that nuclear fusion has occurred inside a fusor device is to use a Geiger counter to measure the gamma ray radioactivity that is produced from a sheet of aluminum foil.
3. Materials analysis: Main article: neutron activation analysis. Neutron activation analysis is one of the most sensitive and accurate methods of trace element analysis. It requires no sample preparation or solubilization and can therefore be applied to objects that need to be kept intact such as a valuable piece of art.
4. The potential use of photonuclear reactions for a range of applications is described. These are photonuclear transmutation doping of semiconductors, neutron production from electron linacs, quality checking of radioactive waste, fission product incineration, photoexcitation of isomers for dosimetry, and nuclear resonance fluorescence for materials analysis.