Stars are natural fusion reactors, and repeated fusion processes occur in them at enormous temperatures. In nuclear fusion, obtained from laboratory research, people have high hopes for the production of energy in the future, and the Americans will announce a big discovery on this topic on Tuesday. But what is nuclear fusion, why is it so complicated and what is the “Holy Grail” when it comes to the energy of the future.

What is nuclear fusion and how does it differ from fission

Stars are natural fusion reactors, and a German physicist named Hans Bethe described in 1939 how they glow by converting hydrogen nuclei into helium nuclei with other particles also involved in the transfer. Inside the stars, heavier elements are created gradually, step by step, by multiple fusions, as per the recipe. Larger and larger nuclei are formed by burning first hydrogen, then helium, then other elements lighter than iron, and finally elements heavier than iron.

Nuclear fusion is the process in which two atomic nuclei react to form a new nucleus that is heavier (with more mass) than the original nuclei. Other subatomic particles are also formed as a result of fusion. As a result of fusion, nuclei of lighter atoms combine to form heavier ones.

If pushed hard enough, hydrogen nuclei can combine to form helium, releasing a lot of energy.

Its proponents consider nuclear fusion the “energy of the future” because it produces little waste and emits zero greenhouse gases.

Fusion differs from fission, which is a nuclear reaction that splits a nucleus into two fragments of roughly equal mass, fast neutrons, radiation, and heat energy.

Fusion is the reverse process: the fusion of two light atomic nuclei into a heavy one. The two isotopes (atonic variants) of hydrogen lead to the formation of helium, and this process also occurs in stars, including our Sun.

Why is nuclear fusion so difficult?

Fusion of even the lightest nuclei is extremely difficult because it requires extremely high temperatures and enormous pressures, so fusion occurs naturally only in extreme places such as the Sun and other stars.

Well, physicists are trying to recreate these extreme conditions in fusion reactors to produce energy. But there is still a lot of work, because even the most modern devices consume more energy than they produce.

Fusion reactors are touted as the “Holy Grail” of energy production because fusion reactions pollute the environment very little and, if they worked, would be very efficient. It would take very few atoms to produce huge amounts of energy, and the result would be very little waste, and by no means anything as dangerous as the superheavy elements left over from fission reactors.

Generating electricity from fusion also produces no greenhouse gases and promises a reliable renewable energy source, provided the reactor fuel, hydrogen and deuterium, can be produced.

Given the very high temperatures, the main difficulty lies in controlling the extremely hot gases

Some key dates in the history of nuclear fusion

1920: Eddington applies the idea of ​​fusion to stars

1932: Hydrogen synthesis demonstrated in the laboratory

1939: Hans Bethe describes the processes of stellar fusion

1946/1954: Fred Hoyle explains the production of heavier elements

1957: Four physicists publish a famous paper on nucleosynthesis

An unusual discovery

The US Department of Energy (Department of Energy) will announce on Tuesday a “major scientific discovery” in the field of nuclear fusion, such publications as the Financial Times and AFP write.

In fact, the Lawrence Livermore National Laboratory near San Francisco recently achieved “net energy gain” on an experimental nuclear fusion reactor. This would be the first time that researchers were able to produce more energy in a nuclear fusion reaction than the amount of energy consumed during the process, which would be an important discovery in the field of research related to obtaining an environmentally clean energy source.

The fusion reaction, which produced a net energy gain of 20 percent, took place over the past two weeks, the FT reported, citing three people with knowledge of the preliminary results of the experiment.

“Ignition” is the moment when the energy produced exceeds that used to cause the reaction. Work on this has been going on for several decades, investments in this direction are made not only in the USA, but also in Russia and Western Europe.

It will be a long time before such “net energy gain” reactions are readily available in large quantities, as the equipment investment will be huge and there are many technical challenges to overcome.

LLNL’s facilities consist of nearly 200 lasers the size of three football fields aimed at a tiny spot where they send high levels of energy to initiate a fusion reaction.

For part of the content of this article, I used information from the book 50 Ideas You Need to Know – Physics by Joan Baker.

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