“Nuclear battery” can last ten thousand years? From how it works, you can learn the truth

With the continuous development of science and technology, mobile phone has become a necessary tool for every modern person. People use it to contact and entertainment. However, when enjoying the convenience brought by mobile phones, the power of mobile phones has become a headache for many people, because under high-intensity use, many mobile phones must be charged several times a day. < / P > < p > and in this case, people began to look at the “nuclear battery”, fantasy mobile phones can use it. Perhaps in the eyes of many people, the power generated by “nuclear battery” is almost endless, and some even claim that it has 10000 years of battery life. But is that really the case? < / P > < p > to know the answer to this question, we must first understand what “nuclear battery” is. The real name of nuclear battery is “radioisotope thermoelectric generator”, which is called “RTG” in English. < / P > < p > most nuclear cells require a radioactive element called plutonium, which is very dangerous because the main material needed is it. However, there is still a difference between the plutonium in nuclear batteries and that in nuclear weapons. The plutonium in nuclear batteries is plutonium-238, which is one neutron less than plutonium-239 in nuclear weapons, which greatly reduces its risk. At least, it will not explode violently, but will slowly decay into uranium-234. During the decay process of plutonium-238 in nuclear cells, alpha particles will be produced. The kinetic energy of these particles will be converted into heat energy, which makes plutonium-238 extremely hot. But this decay process does not release electrons. How does it generate electricity? It is necessary to mention a concept thermoelectric effect, that is, under certain special circumstances, a certain degree of temperature difference can generate current, and nuclear cells use this effect to generate electricity. Up to now, nuclear batteries have been mainly used in space exploration. Although some people tried to install them in pacemakers for decades, the idea was abandoned. < p > < p > because once a person with a nuclear battery pacemaker is accidentally cremated, it will cause pollution to the surrounding environment and organisms, which is very troublesome to deal with. Therefore, only about 100 nuclear pacemakers are actually produced. < / P > < p > during the cold war, NASA and the former Soviet Union used a large number of nuclear batteries to power the probe, which was not because it could last for “10000 years”, but because it could not be affected by sunlight, so as to provide stable power for a long time. In fact, when it comes to space probes, we can easily think of solar cells, because there is no barrier from the atmosphere in outer space, and the intensity of sunlight is much higher than that of the earth, which makes solar energy an inexhaustible energy source. However, the reason why solar energy is not used on a large scale is because of its fatal defect: daylighting. When the detector deviates from the sun or is too far away from the sun, the solar cell is almost equivalent to scrapping, but nuclear energy does not have such a problem. In 1977, NASA launched Voyager 1 and Voyager 2 in order to observe and explore other planets in the solar system and to leave evidence of human existence in the deep space. < / P > < p > because the two of them are flying too far away from the sun, scientists have installed three nuclear batteries on them. Because isotope decay can produce high temperature, in order not to affect the normal operation of the two detectors, scientists installed three nuclear batteries on one of their cantilever. < / P > < p > in fact, it’s not just voyagers that have nuclear batteries, but some familiar probes, such as curiosity, Pioneer 10, Pioneer 11, and so on. < / P > < p > even in the Apollo program, nuclear batteries were used in many places, such as instruments used to measure lunar earthquakes, instruments to measure the magnetic force on the lunar surface, and so on. < / P > < p > as can be seen from the figure below, the Apollo 12 astronauts are taking out the nuclear batteries and preparing to put them in the radiator on the ground. Because the nuclear battery can continuously generate heat, if the excess heat is not radiated out, it will cause certain damage to the equipment. < p > < p > with a preliminary understanding of nuclear batteries, let’s go back to the question at the beginning of the article: can nuclear batteries really achieve 10000 years of battery life? Unfortunately, it’s a distant fantasy. < p > < p > the “fuel” of nuclear cells, plutonium-238, is a kind of radioisotope. Its half-life is about 87.7 years, which means that as long as the “fuel” of plutonium-238, half of plutonium-238 will be converted into uranium-234 after 87.7 years, and half of plutonium-238 will become uranium-234 after 87.7 years. < / P > < p > although it may still be heating at that time, it can no longer produce the current intensity for human use, that is to say, it is already a “waste product”. < / P > < p > from this point of view, the nuclear batteries carried on the spacecraft used are only about 100 years old, but this is enough because most parts of the sensors have no service life of 100 years at all. Generally speaking, the principle of nuclear cell power generation is essentially different from that of ordinary nuclear power generation, because it does not use the heat energy generated by nuclear fission or nuclear fusion, but uses the heat energy generated by isotope decay for power generation. It has not been used for thousands or 10000 years, but more than 100 years at most. Due to the danger of nuclear battery and the high cost, nuclear battery will only be used in aerospace field in the foreseeable future, and it is almost impossible to be used for civilian use. Therefore, friends who hope to use nuclear batteries in mobile phones or cars may be disappointed. Continue ReadingStraight screen S20! Samsung Galaxy S20 Fe exposure: 1Hz high brush + snapdragon 865