What is a radioisotope thermoelectric generator?

Radioisotope thermoelectric generator (RTG) is a source of electricity that uses the heat produced by radioactive disintegration. Radioisotope thermal generators are not nuclear reactors and do not use nuclear cleavage or fusion for energy, although they are still highly radioactive. Radioisotope thermal generators are used when other energy sources are too expensive or impractical, for example on a spacecraft and an automated lighthouse and radar systems. Radioactive material must produce enough heat to provide a significant amount of electricity; At the same time, it must not decompose so quickly that after several years the thermal generator of the radioisotope is unnecessary. Plutonium-238 is the most common isotope used for radioisotope thermal generators, although the Strontium-90 and others have been used in the past. It is expensive to produce plutonium-238, but emits low-penetration alpha radiation, which is much easier to protect against radiation produced by other isotopes.

to convert heat into electricity usesIt eats thermocoupler thermal generators, semiconductor equipment that can convert differences in temperature directly to electricity. Although thermocoups are resistant and have no moving parts, they are very inefficient and change less than 10% of the heat available to electricity. Over time, thermocoups gradually degrade and increase losses caused by the slow disintegration of radioactive material.

Thermal generators of radioisotope are very expensive compared to other energy sources, but are useful in isolated systems without other energy supply, such as interplanetary spacecraft and unmanned radio beacons. The thermal generator of the radioisotope can produce electricity for decades, without external input or outsidue maintenance until the radioactive material has disintegrated or disappoints electronics. Using thermal generators of radioisotope on a spacecraft on board like CassinI, caused many environmental groups protested against the use of radioactive material in space; If the rocket launched Cassini, there was a small chance that Plutonium could have been released into the atmosphere.