China is advancing at breakneck speed in nuclear fusion. It already has something ready that until now only the Netherlands had

The path to a destination as challenging as it is nuclear fusion commercial must necessarily be full of small conquests. Of achievements that may seem modest, but that, in reality, are milestones that put us a little closer of an ambitious objective that seeks nothing more than to help us solve our energy needs without continuing to emit greenhouse gases.

In this context ITER attracts much of the attention. And it is understandable that this is so. After all, it is a project of enormous magnitude, which is also led by the European Union. In fact, this organization is jointly assuming approximately 50% of the total cost of a plan in which the United States, Russia, China, Japan, India and South Korea also participate.

However, the public commitment to nuclear fusion is not condensed solely into ITER. And it is not limited only to the European Union either. Not at all. Europe is signing up very important scientific milestonesbut there are other countries that are also bidding very high, and that, precisely, do not move in the orbit of the West. In fact, two of them, probably the most advantaged, are China and South Korea.

China has a very sophisticated linear plasma generator to advance fusion

In the field of nuclear fusion, plasma is the extremely hot gas that contains the nuclei of deuterium and tritium, the two isotopes of hydrogen, which are involved in the reaction. For these nuclei to overcome their natural electrical repulsion and the strong nuclear interaction to fuse them, they must acquire a very high kinetic energy. And this is only possible if the plasma reaches a temperature equal to or greater than 150 million degrees Celsius.

As we can guess, very few known materials are capable of withstanding such a high temperature. However, this is not all. When a deuterium nucleus fuses with a tritium nucleus, they produce a helium nucleus and a neutron that is ejected with an energy of about 14 MeV (megaelectronvolts). The problem is that the neutron lacks a net electrical charge, so it cannot be confined inside the magnetic field which, however, does manage to retain the deuterium and tritium nuclei, which have a positive electrical charge.

This is the reason why when it originates as a result of the nuclear fusion reaction, this neutron is ejected towards the walls of the vacuum chamber with enormous energy. This particle is very important because in practice it will be closely linked to the production of electrical energy in nuclear fusion reactors, but, at the same time, it represents a very aggressive form of radiation that can significantly degrade the materials used in the reactor. .

The components that will be most affected by the direct impact of high-energy neutrons and the most intense heat flow are the inner wall of the vacuum chamber and the blanketwhich is a mantle that covers it and whose purpose is regenerate tritium which is necessary to use as fuel in the nuclear fusion reaction. This is why it is crucial to develop new materials that are able to withstand the neutron flux and therefore ensure that the reactor will have a long operational life.

Until now, only the Netherlands had a device capable of generating a high-flow plasma similar to what occurs in the vacuum chamber of a nuclear fusion reactor. But now China has it too. The Hefei Institute of Physical Sciences has successfully built a highly advanced linear plasma generator capable of accurately recreating the extreme conditions found inside fusion reactors.

Its purpose is to use it to test candidate materials to be used in vacuum chamber constructionfor which it is essential to subject them to the interaction of plasma. Fortunately, China has confirmed that this machine will be available for international collaboration.

Image | Hefei Institutes of Physical Science

More information | Hefei Institutes of Physical Science

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