Gamma radiation is a decaying emission of pure energy. Unstable nuclei that undergo gamma decay are the product of other types of radioactivity (alpha and beta decay) or of some other nuclear process, such as neutron capture in a nuclear reactor. Because nuclear reactions involve the breaking of very powerful intra-nuclear bonds, massive amounts of energy can be released.
The global nuclear detection architecture is a framework for detecting (through technical and non-technical means), analyzing and reporting nuclear and other radioactive materials that are beyond regulatory control. The threat of radiological attacks has led several organizations to develop specially designed nuclear detection systems.
A major environmental concern related to nuclear energy is the creation of radioactive waste such as tailings from uranium mills, spent (used) reactor fuel, and others. At high doses, ionizing radiation can cause immediate harm to a person's body, including, at very high doses, radiation sickness and death.
The device determines the density of the material by counting the number of photons emitted by a radioactive source (cesium-13) that are read by the detector tubes in the base of the meter. A time interval of 60 seconds is normally used for the counting period.