Encyclopedia business card? Radioactive isotope battery "Radioactive isotope battery" is referred to as isotope battery (Nuclear battery or Atomic battery). There are more than a dozen mechanisms for converting the decay energy of radioisotopes into electrical energy, such as "radioisotope thermoelectric generator (RTG), "radiation volt effect", "decay coupled magnetic resonance", "Reciprocating oscillating cantilever beam", "thermal ion emission", "decay energy-light energy-electric energy", etc.
Contents Introduction to radioisotope battery principles Development history of RTG radioisotope batteries Radioisotopes of nuclear batteries. Application of radioisotope battery Radioisotope battery and Apollo spacecraft Introduction to the development of my country's first plutonium-238 isotope battery Principle of radioisotope battery Development history of RTG radioisotope battery Radioisotope of nuclear battery Application of radioisotope battery Radioisotope battery and Apollo The launch of my country's first plutonium-238 isotope battery on the spacecraft
Edit this section Introduction The radioactive isotope thermoelectric generator was successfully developed by American scientists on January 16, 1956. It was the first successful isotope battery. Immediately. It is used to power various spacecraft equipment in the United States, reduce launch weight and ensure continuous operation of equipment. It is a key technology and product in the leading position of the United States aerospace industry. This thermoelectric generator is made of some excellent semiconductor materials, such as telluride. Bismuth, lead telluride, germanium-silicon alloy and selenium compounds are composed of many materials connected in series. In addition, a suitable heat source and transducer are required to form a temperature difference between the heat source and the transducer to generate electricity. Principles of Radioactive Isotope Batteries in this section The heat source of radioactive isotope batteries is radioactive isotopes. During their transformation process, they will continuously emit much greater energy than ordinary matter in the form of rays with thermal energy. A lovely feature. First, the amount and speed of energy released during transformation are not affected by temperature, chemical reactions, pressure, and electromagnetic fields in the external environment. Therefore, nuclear batteries are known for their strong anti-interference and accurate and reliable operation. Another feature is that the decay time is very long, which determines that the radioactive isotope battery can be used for a long time. The radioactive isotopes used in radioactive isotope batteries mainly include strontium-90 (Sr-90, half-life of 28 years) and plutonium-238 (Pu-). Isotopes with long half-lives such as 238 (half-life: 89.6 years) and polonium-210 (half-life of Po-210 is 138.4 days) are made into a cylindrical battery. The fuel is placed in the center of the battery, surrounded by thermoelectric elements, and the radioactive isotope is emitted. High-energy alpha rays convert heat into electric current in the thermoelectric element. The core of the schematic diagram of the radioisotope battery is the transducer. It uses the principle of thermocouples to perform different functions. The potential difference is generated in the metal to generate electricity. Its advantage is that it can be made very small, but the efficiency is quite low. The current heat utilization rate is only 10 to 20, and most of the heat energy is wasted. In terms of appearance, radioactive isotope batteries have There are many shapes, but the outermost part is made of alloy, which protects the battery and dissipates heat; the second outer layer is a radiation shielding layer to prevent radiation from leaking; the third layer is the transducer, where heat energy is converted into electrical energy; and finally, the heart of the battery, where radioactive isotope atoms are constantly transforming and releasing heat. Edit this paragraph The development history of RTG radioisotope batteries The first radioisotope battery was made by Americans on January 16, 1959. It weighed 1800 grams and could generate 11.6 kilowatt hours of electricity in 280 days. After that, nuclear batteries developed rapidly. The first artificial satellite "Explorer 1" launched by the United States in 1961, the radio transmitter on it was powered by nuclear batteries.
In 1976, the two American spacecrafts "Viking 1" and "Viking 2" landed on Mars successively. In just five months, they obtained more information about Mars than all the information accumulated in human history. Many, their working power source is also a radioactive isotope battery. Because the temperature difference between day and night on the surface of Mars exceeds 100°C, ordinary chemical batteries cannot work due to such a huge temperature difference. Edit this paragraph Radioactive isotopes of nuclear batteries Radioactive isotopes are the heart of nuclear batteries. As the energy source of nuclear batteries, isotope radioactive sources must meet the following conditions:? Long half-life (to ensure the long life of the battery), high power density, It has low radioactive hazard, is easy to process, is economical and easy to shield, etc. There are more than 2,500 kinds of radioactive isotopes, among which there are nearly ten kinds of nuclides that can be used in nuclear batteries, such as 90Sr, 147Pm, 238Pu, 60Co, 63Ni, etc. The most suitable radioisotopes for space applications are radioactive isotopes that emit alpha particles during decay, such as 238Pu? and 210Po. Their external radiation dose is low and the required shielding weight is small, which can greatly save emission costs. The United States currently uses 238Pu on space vehicles. Nuclear batteries used in remote areas can use 90Sr? as the radioactive source. 90Sr is economical and easy to obtain. It is one of the main radioactive wastes of fission reactors and can be extracted from the radioactive waste of nuclear power plants. Only 5,000kg of Sr is produced every year in nuclear power plants around the world. Using it to generate electricity is not only a waste of nuclear power plants The reuse of radioactive isotopes is also a consideration in the era of energy shortage. Edit this section Applications of Radioisotope Batteries Uses in the Sea The depths of the sea are also where radioactive isotope batteries come into play. In the deep sea, solar cells are of no use at all, and the service life of fuel cells and other chemical batteries is too short, so nuclear batteries have to be used. For example, it is now used as a navigation beacon for submarine submarines, which can ensure that the navigation beacon flashes every few seconds, and the battery does not need to be replaced for decades. Nuclear batteries are also used as power sources for underwater monitors to monitor the activities of enemy submarines. Others use nuclear batteries as relay station power supplies for submarine cables. They can withstand the high voltage of five or six kilometers deep sea, work safely and reliably, and cost less, which is very satisfying. Medical Uses In medicine, radioisotope batteries have been used in pacemakers and artificial hearts. Their energy source needs to be precise and reliable so that they can be placed in a patient's chest for long-term use. In the past, when the energy problem could not be solved, people could only put energy outside the body. However, the pipeline connecting the outside to the body has become an important channel of infection, which is very troublesome. Well now, the miniature nuclear battery currently implanted in the human body is made of tantalum-platinum alloy shell and contains 150 mg of plutonium-238. The entire battery weighs only 160 grams and has a volume of only 18 cubic millimeters. It can be used continuously for more than 10 years. Edit this paragraph Radioisotope Battery and Apollo Spacecraft On July 21, 1969, humans successfully landed on the moon for the first time, using the Apollo 11 spacecraft. After landing in the "Sea Tranquility" on the lunar surface, a series of scientific experiments were conducted, such as collecting rock samples, measuring solar wind, etc. Many people may still remember that at that time, people held their breath watching the first human landing on the moon on the TV screen, watching the touching scene of Captain Armstrong and pilot Odlin dancing on the moon. On the Apollo 11 spacecraft, two radioisotope devices were installed, with a thermal power of 15 watts and using plutonium-238 as fuel. However, the radioisotope device on Apollo 11 was used for heating the spacecraft when it spent the night on the moon, which means that it was only used to provide a heat source. Therefore, this device is also called the ALRH (Apolo Lunar RI Heater) device, which means the radioisotope heater used by Apollo on the moon. However, the radioactive isotope devices installed on the Apollo spacecraft that were later launched to explore the lunar surface were all used to generate electricity. This is the SNAP-27A device. It uses plutonium-238 as fuel, has a designed electrical output of 63.5 watts, the entire device weighs 31 kilograms, and has a designed life of one year.
It is mainly a series of scientific experiments used for Apollo lunar surface exploration. One day on the moon is equal to 27 days on Earth. Night is half the time, and one night is about two weeks on Earth. Solar cells completely stop working during darkness. At the same time, the temperature of the lunar surface facing away from the sun will drop sharply by several hundred degrees, changing from a very hot world to a freezing world. In order for the seismometers, magnetic field meters and other machinery on the satellite to work properly, waste heat must be used for insulation. The SNAP-27A device, a radioisotope battery first installed on the Apollo 12 spacecraft, has a lifespan far exceeding the one year considered in the design and can continuously supply more than 70 watts of power, fully meeting the expected design requirements. Due to the success of this experiment, SNAP-27A devices were installed on Apollo 14 launched in 1970 and subsequent Apollo 15, 16, 17 and other spacecrafts. Radioisotope batteries are extremely valuable, and our country cannot yet produce radioisotope batteries using plutonium-238. More than ten years ago, our country bought a radioactive isotope battery from Russia. It was equivalent in size to a 2# dry cell battery, with an output power of 500mW and a continuous output of more than 200 years. The price at that time was equivalent to 30 million yuan. Scientists opened it under strict protection. The structure seemed very simple, but after several years of research, there was no result and they didn't know how to make it. Edit this paragraph my country's first plutonium-238 isotope battery my country's first plutonium-238 isotope battery has been born at the China Institute of Atomic Energy. The successful development of the isotope battery has filled a long-standing gap in this research field in our country, marking a milestone Our country has taken an important step in the research of nuclear power systems. Isotope batteries use the heat energy released during the decay process of radioactive isotopes and convert it into electrical energy through thermocouples. It has the characteristics of small size, light weight, stable and reliable performance, long working life, and good environmental tolerance. It can be used in space and various special, Provide energy for automatic observation stations or signal stations at high altitudes, on the ground, at sea and under the sea under harsh environmental conditions. Isotope batteries have been used in practical applications in the United States, Russia and other countries for the energy supply of spacecraft. With the further development of our country's space exploration (including the launch of the "Moon Landing Plan") and the demand for future deep space exploration, providing stable and lasting energy for our country's spacecraft has been put on the agenda. As so far, spacecraft instruments, Isotope batteries, the ideal power supply source for equipment, have become an important symbol of the progress of aerospace technology. It is particularly important to master a series of key technologies for the preparation of isotope batteries and have independent research and development and production capabilities. In 2004, the Institute of Isotope of the Institute of Atomic Energy undertook the task of "development of a 100-milliwatt-class plutonium-238 isotope battery". It had to complete the overall design and a series of related process studies and develop samples within two years. The Institute of Isotope and collaborating units have carried out a large number of simulation experiments, tracer experiments, thermal experiments and other work according to the formulated research plan. The final test showed that the battery performance fully met the technical index requirements, and all indicators of radiation protection testing met national safety requirements. China's first plutonium-238 isotope battery was born. The successful development of my country's first plutonium-238 isotope battery is a major breakthrough in the field of nuclear power system research, laying a solid foundation for the continued exploration and development of space energy.
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Principle of radioisotope battery The heat source of radioisotope battery is radioactive isotope. During their transformation process, they will continuously emit energy in the form of rays with thermal energy, which is much greater than that of ordinary matter. This great energy has two endearing characteristics. First, the amount and speed of energy released during transformation are not affected by temperature, chemical reactions, pressure, and electromagnetic fields in the external environment. Therefore, nuclear batteries are known for their strong anti-interference and accurate and reliable operation. Another feature is that the decay time is very long, which determines that radioisotope batteries can be used for a long time.
The radioactive isotopes used in radioisotope batteries mainly include strontium-90 (Sr-90, half-life of 28 years), plutonium-238 (Pu-238, half-life of 89.6 years), polonium-210 (Po Isotopes with half-lives as long as -210 (half-life 138.4 days). Make it into a cylindrical battery. The fuel is placed in the center of the battery and surrounded by thermoelectric elements. Radioactive isotopes emit high-energy alpha rays and convert heat into electric current in the thermoelectric elements. ? (This is the principle)