Scientists in South Korea have achieved a major breakthrough in nuclear fusion research by creating a mini Sun that is hotter than the core of our star. The mini Sun was produced by a device called KSTAR, which stands for Korea Superconducting Tokamak Advanced Research.
Nuclear fusion is the process that powers the Sun and other stars. It involves fusing light atomic nuclei, such as hydrogen, into heavier ones, such as helium, releasing enormous amounts of energy in the process. Unlike nuclear fission, which splits heavy atoms into lighter ones and generates radioactive waste, nuclear fusion is clean and virtually limitless. However, achieving nuclear fusion on Earth is extremely challenging, as it requires extremely high temperatures and pressures to overcome the natural repulsion between positively charged nuclei.
Nuclear fusion has been a long-standing goal of scientists and engineers, as it could provide a sustainable and carbon-free source of energy for the future. However, so far, no fusion reactor has been able to produce more energy than it consumes. The most advanced fusion project in the world is the International Thermonuclear Experimental Reactor (ITER), which is being built in France by a consortium of 35 countries. ITER aims to achieve a net energy gain of 10 times by 2035.
How did the Korean team create a mini Sun?
The Korean team used a device called a tokamak, which is a doughnut-shaped chamber that uses powerful magnetic fields to confine a plasma, a state of matter where atoms are stripped of their electrons. By heating and compressing the plasma, the team was able to induce nuclear fusion reactions, creating a mini Sun inside the tokamak.
The team reported that they were able to sustain a nuclear fusion reaction running at temperatures in excess of 100 million degrees Celsius for 30 seconds for the first time. This is remarkable, as it is nearly seven times hotter than the core of the Sun, which has a temperature of 15 million degrees Celsius. The team also achieved a net energy gain, meaning that they produced more energy than they consumed, which is a key milestone for fusion research.
The team’s achievement was published in the journal Science Advances, where they explained how they used a novel technique called the “suppression of edge localized modes (ELMs)” to stabilize the plasma and prevent it from escaping the magnetic field. ELMs are instabilities that occur at the edge of the plasma and can cause sudden bursts of heat and particles, damaging the tokamak walls and disrupting the fusion process. The team used a rotating magnetic field to suppress the ELMs and maintain a steady plasma state.
What are the implications and challenges of this breakthrough?
The team’s breakthrough is a significant step forward for nuclear fusion research, as it demonstrates the feasibility and potential of achieving a stable and efficient fusion reaction on Earth. The team’s results also provide valuable insights and data for the ITER project, which uses a similar tokamak design and aims to achieve a fusion reaction lasting for several minutes.
However, there are still many challenges and obstacles to overcome before nuclear fusion can become a viable and commercial source of energy. For instance, the team’s mini Sun only lasted for 30 seconds, which is far from the continuous and reliable operation that is needed for a power plant. Moreover, the team’s tokamak is much smaller than the ITER tokamak, which has a diameter of 30 meters and a volume of 840 cubic meters, compared to the KSTAR tokamak, which has a diameter of 3.6 meters and a volume of 14 cubic meters. Scaling up the fusion reaction to a larger size and maintaining the high temperature and pressure conditions will require more advanced technology and engineering.
The team plans to continue their research and experiments, aiming to extend the duration of the fusion reaction to 300 seconds by 2025. They also hope to collaborate with other fusion researchers around the world and contribute to the global effort of achieving clean and abundant energy from nuclear fusion.