According to Yahoo News on the 2nd, the world's largest experimental fusion reactor began operating in Japan on the 1st, taking another step towards achieving an "artificial sun". On the afternoon of the 1st, the Japanese quantum science and technology research and development institution, Naka Research Institute, held a ceremony to begin the operation of the large-scale nuclear fusion experimental device JT-60SA. This six story machine is located in a hangar in Naka City, Ibaraki Prefecture, Japan. It consists of a donut shaped tokamak container containing rotating plasma heated to 200 million degrees Celsius. EU Energy Commissioner Kadrie Simpson stated that the JT-60SA is "the world's most advanced tokamak device" and called its operation a "milestone in the history of fusion.". Simson also stated that fusion has the potential to become a key component of the energy structure in the second half of this century. The JT-60SA program is a joint construction project between the European Union and Japan, and is a pioneering project of the International Thermonuclear Experimental Reactor Program (ITER, also known as the "Artificial Sun" program). The goal of the JT-60SA reactor is to study the feasibility of fusion as a safe, large-scale, and carbon free net energy source, so that it generates more energy than it consumes. The ultimate goal of both projects is to fuse the internal hydrogen nuclei into helium, releasing energy in the form of light and heat, simulating the processes that occur inside the Sun. Nuclear fusion can be carried out in different ways, and its process is much cleaner than nuclear fission, without producing radioactive waste. If an economic fusion reaction is achieved, it will greatly reduce or even completely eliminate human dependence on fossil fuels. Last year, scientists at the Lawrence Livermore National Laboratory in the United States achieved a "net energy gain" in fusion reactions, which means that the energy generated by the reaction (3.15 megajoules) is greater than the initial energy provided for the reaction (2.05 megajoules), which is a significant achievement. Although every progress in nuclear fusion can cause a sensation, the road ahead is still long. (Lai Xin She)