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What is a radioisotope thermoelectric generator?

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A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — transuranium element Modern version of the periodic table of the elements (printable).

A radioisotope thermoelectric generator (RTG) is a type of thermoelectric power generator that utilizes the heat produced by the decay of radioactive isotopes to generate electricity.12

These devices function through direct power conversion, where the heat generated by nuclear decay flows through a thermoelectric converter to a heat sink, creating a temperature differential that produces direct current (DC) electricity. Because they are reliable, long-lasting, and relatively immune to radiation, they are ideal for remote or unattended applications where traditional power sources are impractical.13

Common uses include:
* Space Exploration: Providing electrical power for spacecraft missions to outer planets and equipment placed on the Moon.14
* Remote Monitoring: Powering isolated weather stations and deep-ocean data collection systems.1
* Medical Devices: Historically used to power cardiac pacemakers.14

Alpha-emitting isotopes with half-lives ranging from several months to over 100 years, such as plutonium-238 and curium-244, are preferred for these generators because they require less shielding than beta- or gamma-emitting isotopes.4