Shulou(Shulou.com)11/24 Report--

Beijing, December 14 (Xinhua) according to reports, the U.S. Department of Energy (DOE) announced on Tuesday local time that researchers have made a historic breakthrough in nuclear fusion, achieving a "net energy gain" from an experimental nuclear fusion reactor for the first time, which makes many people hopeful that more clean energy will be generated in the future.

The breakthrough was made by researchers at the National Ignition device (NIF) at Lawrence Livermore National Laboratory (LLNL) in California on December 5. Nuclear fusion may be a new concept to many people, but scientists have been studying it since the 1940s. However, researchers face a serious challenge: how to produce more energy (higher than the energy consumed), which is almost an insurmountable challenge to this day.

This time, the researchers injected 2.05 megajoules of energy into the target, resulting in a fusion energy output of 3.15 megajoules, which is more than 50% higher than the input energy. This is also the first time that researchers have achieved meaningful energy growth in the experiment.

What is nuclear fusion? Nuclear fusion is the process of combining two lighter elements to form heavier elements. This is in the same way that the sun provides energy, in which protons of hydrogen atoms collide violently in the core at incredible temperatures and merge to produce helium atoms.

On Earth, nuclear fusion is achieved by the fusion of elements deuterium (heavy hydrogen) and tritium (superheavy hydrogen). Deuterium is so abundant that it can be found in water, especially in the ocean. The content of tritium is low, which mainly exists in our atmosphere, which is the result of cosmic radiation. In addition, tritium can also be produced in nuclear explosions and is a by-product of nuclear reactors.

The sun's huge gravity enables it to fuse hydrogen atoms, but to create fusion on Earth, scientists need to apply a temperature and extremely high pressure of about 100 million degrees Celsius, 10 times higher than the temperature of the sun's core.

Although there are different ways to try to produce nuclear fusion, researchers at the National Ignition device (NIF) at Lawrence Livermore National Laboratory (LLNL) used 192 lasers to focus on the inner wall of a cylinder with a very small "capsule" device containing fusion fuel: deuterium and tritium. When the laser hits the target, they produce X-rays, then squeeze the fuel, evaporating the "capsule" device in a very short time, and the resulting shock wave shatters hydrogen atoms, causing them to fuse and release energy.

Although the energy generated this time is very small, about 3 megajoules (enough to power a light bulb), it marks the historic first time of nuclear fusion energy, because the laser emits only slightly more than 2 megajoules of energy, that is, the energy generated. More than 50% higher than the input energy.

How is it different from existing nuclear energy? When it comes to nuclear energy, many people may think of the nuclear reactors we have today. But the difference is that these reactors use "fission".

Fission is the opposite of fusion, which forces atoms to gather together, while nuclear reactors (fission) generate energy by separating heavy atoms.

Nuclear fusion can also generate clean energy. Unlike nuclear reactors, this process does not produce by-products, such as spent fuel rods (spent rod) found in nuclear power plants.

In addition, unlike fission, nuclear fusion does not cause nuclear meltdown and cannot be used to make nuclear weapons.

The International Atomic Energy Agency (IAEA) also explained that although the hydrogen bomb did use fusion reaction, a second fission bomb was needed to detonate it.

Why is nuclear fusion important? At present, the earth is facing a climate crisis caused by the burning of fossil fuels for centuries. As a result, floods, droughts and sea-level rise will intensify. We have seen this happening, and the warmer the earth gets, the more serious these disasters will become.

Today, the earth has warmed by about 1.2 degrees Celsius. According to the goals set by the 2015 Paris Climate Agreement, we should limit it to 1.5 degrees Celsius by the end of the century in order to reduce climate-related disasters. As a result, scientists and engineers have been working hard to develop cost-effective clean energy.

This is the opportunity for nuclear fusion to display its talents. It does not produce harmful carbon dioxide or methane and is very efficient. According to the International Atomic Energy Agency (IAEA), fusion produces four times as much energy per kilogram of fuel as fission and nearly 4 million times as much as burning oil or coal.

"this is a landmark achievement that brings us closer to having an abundance of zero-carbon fusion energy to help people solve some of mankind's most complex and urgent problems, including the provision of clean energy to combat climate change," Jennifer Granholm, US energy secretary, said in a statement on Tuesday.

When can fusion be used as a source of energy? Although this is the first time in history, it does not mean that we are ready to produce energy on a large scale.

Kim Budil, director of Lawrence Livermore National Laboratory (LLNL), says this achievement is one of the most significant scientific challenges that mankind has ever solved. However, so far, there are no small obstacles, both in science and technology.

Budil said: "this is just an experimental result, in order to achieve commercial fusion energy, we must continue to produce such results, there must be a strong driver system to achieve this." . She added that although it would not take as long as some scientists had expected, it would take at least decades to develop enough basic technology to build a nuclear substation.

In addition to the United States, there are other countries that are studying nuclear fusion. In France, there is a cooperative International Thermonuclear Experimental reactor (ITER), a large fusion reactor weighing 23000 tons and nearly 30 meters high, which is scheduled to start operation in about 10 years' time.

In Canada, private companies such as General Fusion are also working on the technology. In addition, some private enterprises in China, Britain and Germany are committed to fusion research.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.