A key component for the ongoing nuclear fusion reactor project, known as the "artificial sun", a superconducting coil built by Chinese scientists and engineers, arrived in southern France on Friday, according to its builder, the Institute of Plasma Physics under the Chinese Academy of Sciences.

The coil, poloidal field coil #6, will be the first and heaviest among six to be installed during the International Thermonuclear Experimental Reactor machine assembly phase, according to the project's official website.

With a weight of 400 tons, it will work to provide a stable and super strong magnetic field in a vessel to hold the extremely hot plasma created by nuclear fusion, according to the Institute of Plasma Physics based in Hefei, capital of East China's Anhui province.

Temperature is considered one of the most important conditions for nuclear fusion reactions. In 2018, the Hefei institute had for the first time achieved a plasma central electron temperature of 100 million degrees Celsius.

In Cadarache, Provence, in southern France, 35 nations are collaborating to build the world's largest magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy based on the same principle that powers the sun and stars, according to the project.