Radioisotope thermal generator - Revision history

Jmdonev at 20:58, 18 April 2022

2022-04-18T20:58:32Z

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	==Advantages==		==Advantages==
	RTGs have been deployed on space probes throughout the [[solar system]]. The two ~~principle~~ uses are space missions mainly where solar panels would be ineffective and in remote unmanned outposts. Remote lighthouses in Russia have made extensive use of RTGs. Conventional power generation and transportation to and from these locations would be difficult.		RTGs have been deployed on space probes throughout the [[solar system]]. The two principal uses are space missions mainly where solar panels would be ineffective and in remote unmanned outposts. Remote lighthouses in Russia have made extensive use of RTGs. Conventional power generation and transportation to and from these locations would be difficult.

	Most RTG designs have no moving parts which allow for reliable, long-term operation.		Most RTG designs have no moving parts which allow for reliable, long-term operation.

Jmdonev: 1 revision imported

2021-10-18T16:14:34Z

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energy>Luisa at 22:21, 17 October 2021

2021-10-17T22:21:34Z

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	[[Category:Translated to Spanish]]		[[Category:Translated to Spanish]]
	[[es:~~Generadores termoeléctricos~~ de radioisótopos]]		[[es:Generador termoeléctrico de radioisótopos]]

Jmdonev: 1 revision imported

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energy>Jmdonev at 01:58, 27 May 2021

2021-05-27T01:58:16Z

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			[[Category:Done 2021-01-31]]
	[[File:Cassinirtg.jpg\|360px\|thumb\|right\|Figure 1. This is the RTG used on NASAs Cassini probe.<ref>Wikimedia Commons. (May 17, 1997). ''RTG Radiation Measurement'' [Online]. Available: https://commons.wikimedia.org/wiki/File:RTG_radiation_measurement.jpg</ref>]]		[[File:Cassinirtg.jpg\|360px\|thumb\|right\|Figure 1. This is the RTG used on NASAs Cassini probe.<ref>Wikimedia Commons. (May 17, 1997). ''RTG Radiation Measurement'' [Online]. Available: https://commons.wikimedia.org/wiki/File:RTG_radiation_measurement.jpg</ref>]]

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	==References==		==References==
	{{reflist}}[[Category:Uploaded]]		{{reflist}}
	[[Category:~~Done 2020-05-30~~]]		[[Category:Uploaded]]

			[[Category:Translated to Spanish]]
			[[es:Generadores termoeléctricos de radioisótopos]]

Jmdonev at 00:02, 28 October 2020

2020-10-28T00:02:20Z

← Older revision		Revision as of 00:02, 28 October 2020
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	Most RTG designs have no moving parts which allow for reliable, long-term operation.		Most RTG designs have no moving parts which allow for reliable, long-term operation.

	The main differences between RTGs and fission reactors are weight, lifetime, and power output. The first Soviet TOPAZ reactors in 1971 were capable of producing 5 kW of electrical power for 3-5 years and weighed 320 kilograms. Around the same time, a Systems for Nuclear Auxiliary Power-19 (SNAP-19) RTG weighed only 14 kilograms and had an initial power output of 40 [[MWe\|Watts electric]].<ref>Fusion Technology Institute.''Comparison of USSR and US Fission Space Reactors'' [Online]. Available: http://fti.neep.wisc.edu/neep602/SPRING00/lecture35.pdf</ref> Four of them together produced enough power to last 30 years on Pioneer 10 and 22 years on Pioneer 11. The Voyager satellites (launched in 1977) were each equipped with three MHW-RTGs, providing them ~~initially~~ with 470 Watts ~~initially~~, with expected lifetimes of approximately 48 years (taking into account the satellites powering down systems so as not to have greater electrical load than supply), and each weighing 37.7 kilograms.<ref>NASA. (December 14, 2017). ''The Pioneer Missions'' [Online]. Available: https://www.nasa.gov/centers/ames/missions/archive/pioneer.html </ref> Currently, a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG, the RTG on the Curiosity rover) weighs 35.5 kilograms and has a life expectancy of 14 years.<ref>NASA. (October 2013). ''Multi-Mission Radioisotope Thermoelectric Generator.'' [Online]. Available: https://mars.nasa.gov/mars2020/files/mep/MMRTG_FactSheet_update_10-2-13.pdf</ref>		The main differences between RTGs and fission reactors are weight, lifetime, and power output. The first Soviet TOPAZ reactors in 1971 were capable of producing 5 kW of electrical power for 3-5 years and weighed 320 kilograms. Around the same time, a Systems for Nuclear Auxiliary Power-19 (SNAP-19) RTG weighed only 14 kilograms and had an initial power output of 40 [[MWe\|Watts electric]].<ref>Fusion Technology Institute.''Comparison of USSR and US Fission Space Reactors'' [Online]. Available: http://fti.neep.wisc.edu/neep602/SPRING00/lecture35.pdf</ref> Four of them together produced enough power to last 30 years on Pioneer 10 and 22 years on Pioneer 11. The Voyager satellites (launched in 1977) were each equipped with three MHW-RTGs, initially providing them with 470 Watts, with expected lifetimes of approximately 48 years (taking into account the satellites powering down systems so as not to have greater electrical load than supply), and each weighing 37.7 kilograms.<ref>NASA. (December 14, 2017). ''The Pioneer Missions'' [Online]. Available: https://www.nasa.gov/centers/ames/missions/archive/pioneer.html </ref> Currently, a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG, the RTG on the Curiosity rover) weighs 35.5 kilograms and has a life expectancy of 14 years.<ref>NASA. (October 2013). ''Multi-Mission Radioisotope Thermoelectric Generator.'' [Online]. Available: https://mars.nasa.gov/mars2020/files/mep/MMRTG_FactSheet_update_10-2-13.pdf</ref>

	RTGs produce low neutron, beta, and gamma radiation compared to reactors. The emissions of these particles cause problems with the instruments on the probes unless their instruments are shielded from the radiation.		RTGs produce low neutron, beta, and gamma radiation compared to reactors. The emissions of these particles cause problems with the instruments on the probes unless their instruments are shielded from the radiation.

	===Three dimensional RTG===		===Three dimensional RTG===
	Please explore the three dimensional models below to see what an RTG looks like and how they're employed in different missions.		Please explore the three-dimensional models below to see what an RTG looks like and how they're employed in different missions.

	<html>		<html>

	<iframe src="https://energyeducation.ca/3dmodels/RTG/" width="100%" height="450px" scrolling="no" frameborder="0" /></iframe></html>		<iframe src="https://energyeducation.ca/3dmodels/RTG/" width="100%" height="450px" scrolling="no" frameborder="0" /></iframe></html>
	Figure 3. A three dimensional model of an RTG that could be used on space missions. ~~Drag the RTG around to view it from different angles and click 'See_Components' to see inside.~~		Figure 3. A three dimensional model of an RTG that could be used on space missions.

	===Cassini Probe===		===Cassini Probe===
	The Cassini probe was a particularly exciting and successful use of an RTG in a space mission. Cassini spent 20 years in space and took almost 500 000 photos of ~~Jupiter~~ and its moons. Cassini opened the door to a greater understanding of the largest ~~planet~~ in our solar system and paved the way for future scientific and exploratory missions.<ref>NASA. (March 28, 2019). ''Cassini'' Available: https://solarsystem.nasa.gov/missions/cassini/overview/</ref>		The Cassini probe was a particularly exciting and successful use of an RTG in a space mission. Cassini spent 20 years in space and took almost 500 000 photos of Saturn and its moons. Cassini opened the door to a greater understanding of one of the largest planets in our solar system and paved the way for future scientific and exploratory missions.<ref>NASA. (March 28, 2019). ''Cassini'' Available: https://solarsystem.nasa.gov/missions/cassini/overview/</ref>

	<html>		<html>
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	==References==		==References==
	{{reflist}}[[Category:Uploaded]]		{{reflist}}[[Category:Uploaded]]
			[[Category:Done 2020-05-30]]

Jmdonev at 17:36, 31 July 2020

2020-07-31T17:36:46Z

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Jmdonev at 18:17, 30 July 2020

2020-07-30T18:17:08Z

← Older revision		Revision as of 18:17, 30 July 2020
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	[[File:Cassinirtg.jpg\|360px\|thumb\|right\|Figure 1. This is the RTG used on NASAs Cassini probe.<ref>Wikimedia Commons. (May 17, 1997). ''RTG Radiation Measurement'' [Online]. Available: https://commons.wikimedia.org/wiki/File:RTG_radiation_measurement.jpg</ref> ]]		[[File:Cassinirtg.jpg\|360px\|thumb\|right\|Figure 1. This is the RTG used on NASAs Cassini probe.<ref>Wikimedia Commons. (May 17, 1997). ''RTG Radiation Measurement'' [Online]. Available: https://commons.wikimedia.org/wiki/File:RTG_radiation_measurement.jpg</ref>]]

	<onlyinclude>Radioisotope Thermoelectric Generators (RTGs) are highly efficient power production systems most often used in long-distance space travel and remote areas on Earth. They produce electricity by the heat emitted from decaying radioactive isotopes. RTGs are most famous for their use on NASA’s Cassini probe, Voyager probes, New Horizons<ref>JPL, Accessed online http://pluto.jhuapl.edu/Mission/Spacecraft/Systems-and-Components.php June 29th, 2020.</ref> and Curiosity rover.<ref>NASA RPS Program. ''Radioisotope Power Systems'' [Online]. Available: https://rps.nasa.gov/ accessed June 29th, 2020.</ref></onlyinclude>		<onlyinclude>Radioisotope Thermoelectric Generators (RTGs) are highly efficient power production systems most often used in long-distance space travel and remote areas on Earth. They produce electricity by the heat emitted from decaying radioactive isotopes. RTGs are most famous for their use on NASA’s Cassini probe, Voyager probes, New Horizons<ref>JPL, Accessed online http://pluto.jhuapl.edu/Mission/Spacecraft/Systems-and-Components.php June 29th, 2020.</ref> and Curiosity rover.<ref>NASA RPS Program. ''Radioisotope Power Systems'' [Online]. Available: https://rps.nasa.gov/ accessed June 29th, 2020.</ref></onlyinclude>

Jmdonev: Created page with "[[File:Cassinirtg.jpg|360px|thumb|right|Figure 1. This is the RTG used on NASAs Cassini probe.Wikimedia Commons. (May 17, 1997). ''RTG Radiation Measurement'' [Online]. A..."

2020-07-29T18:42:17Z

Created page with "[[File:Cassinirtg.jpg|360px|thumb|right|Figure 1. This is the RTG used on NASAs Cassini probe.<ref>Wikimedia Commons. (May 17, 1997). ''RTG Radiation Measurement'' [Online]. A..."

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[[File:Cassinirtg.jpg|360px|thumb|right|Figure 1. This is the RTG used on NASAs Cassini probe.<ref>Wikimedia Commons. (May 17, 1997). ''RTG Radiation Measurement'' [Online]. Available: https://commons.wikimedia.org/wiki/File:RTG_radiation_measurement.jpg</ref> ]]

<onlyinclude>Radioisotope Thermoelectric Generators (RTGs) are highly efficient power production systems most often used in long-distance space travel and remote areas on Earth. They produce electricity by the heat emitted from decaying radioactive isotopes. RTGs are most famous for their use on NASA’s Cassini probe, Voyager probes, New Horizons<ref>JPL, Accessed online http://pluto.jhuapl.edu/Mission/Spacecraft/Systems-and-Components.php June 29th, 2020.</ref> and Curiosity rover.<ref>NASA RPS Program. ''Radioisotope Power Systems'' [Online]. Available: https://rps.nasa.gov/ accessed June 29th, 2020.</ref></onlyinclude>

==Components==
RTGs can be broken down into three critical components; the radioactive isotope, the thermocouples, and the thermal insulation.

====Isotope====
The radioactive isotope is at the core of the RTGs design. It is the component that provides all waste heat in which the rest of the design can produce electricity from. Most often, designs use Plutonium-238, Strontium-90, or Americium-241 for their power density, half-life, and radioactive shielding requirements. Mostly because of the half-lives of the isotopes, RTGs can provide power for decades. For example, Plutonium-238, the most common and famous isotope used on NASA RTGs has a half-life of approximately 90 years.<ref>World Nuclear Association. (December 2018). ''Plutonium'' [Online]. Avaliable: https://www.world-nuclear.org/information-library/nuclear-fuel-cycle/fuel-recycling/plutonium.aspx</ref> Each isotope has advantages and drawbacks, but usually one of these three isotopes will be deposited in pellets at the center of the RTG to which they can then decay and emit heat to the surrounding components.

[[File:RTG diagram.png|thumb|left|Figure 2. This figure shows the components of an RTG.<ref>Wikimedia Commons. (March 15, 2015). ''SiGe RTG'' [Online]. Available: https://commons.wikimedia.org/wiki/File:SiGe_RTG.png</ref>]]

====Thermocouple====
The thermocouple, discovered in 1821 by Thomas Johann Seebeck<ref>Wikipedia. ''Thermocouple'' [Online]. Available: https://en.wikipedia.org/wiki/Thermocouple#Principle_of_operation</ref> is a device that can produce electricity by differences in surrounding temperature. When two different metals are connected and there is a temperature difference between them, a magnetic field is produced. This magnetic field can then be used to produce a current, or flow of electrons, and a resulting voltage and power output. This is the exact fundamental basis used in thermocouples on an RTG. The waste heat produced by decaying isotopes will heat one metal, while the ambient temperature of the RTG and deep space will keep the other metal cool. Just as before, these metals are connected and electricity is produced.

====Thermal Regulation====
The final main component of an RTG is the thermal insulation. Especially important for deep space probes, the device must be able to maintain a certain temperature to keep electronics and moveable parts operating properly. The RTG is covered with many layers of insulation and then a hard outer shell to protect the critical workings of the device. However, not all the waste heat is needed to keep the spacecraft running. As such, most RTGs have radiator fins. Regulating temperatures on an RTG is critical to its proper function and operation. Specific design principles are needed for this task, and temperature regulation makes up a bulk of the outer casings and layers.

==Advantages==
RTGs have been deployed on space probes throughout the solar system The two principle uses are space missions mainly where solar panels would be ineffective and in remote unmanned outposts. Remote lighthouses in Russia have made extensive use of RTGS. Conventional power generation and transportation to and from these locations would be difficult.

An RTG has no moving parts which allow for long-term operation.

The main differences between RTGs and fission reactors are weight, lifetime, and power output. The first Soviet TOPAZ reactors in 1971 were capable of producing 5 kW of power for 3-5 years and weighed 320 kilograms. Around the same time, a Systems for Nuclear Auxiliary Power-19 (SNAP-19) RTG weighed only 14 kilograms and had an initial power output of 40 Watts electric.<ref>Fusion Technology Institute.''Comparison of USSR and US Fission Space Reactors'' [Online]. Available: http://fti.neep.wisc.edu/neep602/SPRING00/lecture35.pdf</ref> Four of them together produced enough power to last 30 years on Pioneer 10 and 22 years on Pioneer 11. The Voyager satellites (launched in 1977) were each equipped with three MHW-RTGs, providing them initially with 470 Watts initially, with expected lifetimes of approximately 48 years (taking into account the satellites powering down systems so as not to have greater electrical load than supply), and each weighing 37.7 kilograms.<ref>NASA. (December 14, 2017). ''The Pioneer Missions'' [Online]. Available: https://www.nasa.gov/centers/ames/missions/archive/pioneer.html </ref> Currently, a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG, the RTG on the Curiosity rover) weighs 35.5 kilograms and has a life expectancy of 14 years.<ref>Wikipedia. ''Multi Mission Radioisotope Thermoelectric Generator.'' [Online]. Available: https://en.wikipedia.org/wiki/Multi-mission_radioisotope_thermoelectric_generator#:~:text=Design%20goals%20for%20the%20MMRTG,14%20years%2C%20and%20minimizing%20weight.</ref>

RTGs produce low neutron, beta, and gamma radiation compared to reactors. The emissions of these particles cause problems with the instruments on the probes unless their instruments are shielded from the radiation.

===Three dimensional RTG===
<html>

<iframe src="https://energyeducation.ca/3dmodels/RTG/" width="100%" height="450px" scrolling="no" frameborder="0" /></iframe></html>
The figure above is a three dimensional model of an RTG that could be used on space missions. Drag the RTG around to view it from different angles and click 'See_Components' to see inside.

===Cassini Probe===
The Cassini probe was a particularly exciting and successful use of an RTG in a space mission.

<html>

<iframe src="https://energyeducation.ca/3dmodels/Cassini/" width="100%" height="450px" scrolling="no" frameborder="0" /></iframe></html>
The figure above is a three dimensional model of the Cassini mission. Note the three different RTGs on the bottom. Drag the image around to view it from different angles.

===New Horizons===
The New Horizons probe was another exciting and successful use of an RTG in a space mission.

<html>

<iframe src="https://solarsystem.nasa.gov/gltf_embed/2363" width="100%" height="450px" scrolling="no" frameborder="0" /></iframe></html>
The figure above<ref>NASA, available https://solarsystem.nasa.gov/resources/2363/new-horizons-3d-model/ accessed July 29th, 2020.</ref> is a three dimensional model of the New Horizons probe. Note the RTG on the bottom. Drag the image around to view it from different angles.

===For Further Reading===
RTGs are extremely useful low power production devices which have paved the wave for more distant and exploratory science. Scientists continue to update design specifications and with every new generation of RTGs, they become more efficient, powerful, and useful. To learn more, visit https://rps.nasa.gov/

* [[Nuclear reactor]]
* [[Nuclear decay]]
* [[Nuclear fission]]
* [[Ionizing radiation]]
*Or explore a [[Special:Random|random page]]

==References==
{{reflist}}[[Category:Uploaded]]
[[category:Zach edit]]