Noun
a radioactive isotope of an element; produced either naturally or artificially
Source: WordNet96 Zr has a half-life of 2.4×10 19 years, and is the longest-lived radioisotope of zirconium. Source: Internet
A synthetic radioisotope is a radionuclide that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. Source: Internet
An incident where water-soluble caesium-137 leaked into the source storage pool requiring NRC intervention citation has led to near elimination of this radioisotope outside of military applications. Source: Internet
Current interplanetary spacecraft power systems (such as radioisotope thermoelectric generators (RTGs)) and solar arrays are incapable of producing that much power. Source: Internet
A polonium-210 radioisotope heater unit was used to keep the rover warm during the long lunar nights. Source: Internet
Gmelin Handbook of Inorganic Chemistry, System No. 71, Volume 7a, transuranics, Part A2, p. 289 Therefore, curium can be used in its common oxide form in radioisotope thermoelectric generators like those in spacecraft. Source: Internet