In a groundbreaking achievement in April 2023, China's "artificial sun" tokamak, known as EAST (Experimental Advanced Superconducting Tokamak), has set a new world record by superheating a plasma loop to temperatures five times hotter than the sun. The state media reported that the tokamak maintained a temperature of 158 million degrees Fahrenheit (70 million degrees Celsius) for an impressive duration of 1,056 seconds, marking a significant step forward in the quest for nearly limitless clean energy.
The feat surpassed the previous record set by France's Tore Supra tokamak in 2003, which sustained similar temperatures for 390 seconds. This accomplishment adds to EAST's previous achievement in May 2021 when it operated at an unprecedented temperature of 216 million F (120 million C) for 101 seconds. In comparison, the core of the actual sun reaches temperatures of approximately 27 million F (15 million C).
Experiment leader Gong Xianzu, a researcher at the Institute of Plasma Physics of the Chinese Academy of Sciences, expressed satisfaction with the recent operation. Gong stated, "The recent operation lays a solid scientific and experimental foundation towards the running of a fusion reactor."
The pursuit of nuclear fusion as a means of generating clean energy has captivated scientists for over 70 years. By replicating the process occurring in stars, where hydrogen atoms fuse to create helium under extreme pressures and temperatures, researchers aim to tap into the vast potential of fusion energy. Stars convert matter into light and heat, producing enormous amounts of energy without harmful greenhouse gas emissions or long-lasting radioactive waste.
However, recreating the conditions found inside stars poses numerous challenges. The most prevalent design for fusion reactors, the tokamak, involves superheating plasma—a state of matter consisting of positive ions and negatively charged free electrons—and confining it within a donut-shaped chamber using powerful magnetic fields.
One of the main obstacles has been containing the turbulent and superheated plasma coils long enough for nuclear fusion to occur. While the concept of the tokamak was introduced by Soviet scientist Natan Yavlinsky in 1958, no experimental reactor has yet achieved net energy gain.
The difficulty lies in handling plasma at the extremely high temperatures required for fusion. Fusion reactors necessitate temperatures many times hotter than the sun, as they operate at significantly lower pressures than those inside stellar cores. While heating the plasma to temperatures hotter than the sun is relatively feasible, the challenge lies in corralling it effectively, preventing it from burning through the reactor walls without compromising the fusion process.
The EAST project is an ambitious endeavor expected to cost China over $1 trillion by its completion in June. It serves as a testing ground for technologies intended for the International Thermonuclear Experimental Reactor (ITER), a larger fusion project currently under construction in Marseille, France. ITER, a collaboration between 35 countries including China, the United States, and numerous European nations, boasts the world's most powerful magnet and is set to become the largest nuclear reactor globally. Its magnetic field will be 280,000 times stronger than Earth's magnetic field. With an anticipated launch in 2025, ITER will provide invaluable insights into the practical aspects of harnessing the power of stars on Earth.
China is also actively pursuing independent programs to develop nuclear fusion power, conducting inertial confinement fusion experiments and planning the completion of a new tokamak by the early 2030s. Similarly, the United States and a British company are making significant strides in fusion technology, with the first viable fusion reactor potentially being completed as early as 2025, while another British company aims to achieve commercial electricity generation from fusion by 2030.
As nations intensify their efforts to unlock the potential of nuclear fusion, the recent breakthrough by China's "artificial sun" tokamak offers renewed hope for a future powered by clean, abundant, and sustainable energy sources.