'Artificial Sun' reaches a temperature of 100 million Celsius

News Excerpt:

Recently the scientists from South Korea have been able to produce heat of temperature 100 million Celsius from their reactor for a record period of 48 seconds.

More About The News:

  • The Korea Institute of Fusion Energy's (KFE) Korea Superconducting Tokamak Advanced Research (KSTAR) fusion reactor has achieved a groundbreaking milestone by reaching temperatures seven times hotter than the Sun's core. During testing between December 2023 and February 2024, the KSTAR reactor sustained temperatures of 180 million degrees Fahrenheit (100 million degrees Celsius) for 48 seconds, surpassing previous records. 
    • This accomplishment demonstrates progress towards sustaining high-temperature plasma, which is crucial for nuclear fusion reactions. Maintaining the high confinement mode (H-mode) for over 100 seconds further showcases KSTAR's capabilities. 
      • H-mode provides a stable plasma state essential for efficient fusion reactions. By employing tungsten diverters instead of carbon, the KSTAR team successfully extended plasma stability. 
  • Nuclear Fusion: Nuclear fusion is a process where two atomic nuclei combine to form a heavier nucleus, releasing a significant amount of energy in the process. The energy released in nuclear fusion is several times greater than that released in nuclear fission, which is the process used in current nuclear power plants. This fusion reaction is the same process that powers the Sun and other stars, generating light and heat. Fusion involves fusing hydrogen and other light elements to release tremendous power, potentially providing unlimited, zero-carbon electricity, which is often referred to as the "holy grail" of the energy transition.
  • Tokamak: A tokamak is a device used to confine and control hot plasma in the process of nuclear fusion. It consists of a torus-shaped chamber surrounded by magnetic coils. Inside the chamber, hydrogen isotopes are heated to extremely high temperatures, forming a plasma. Magnetic fields generated by the coils confine the plasma, preventing it from contacting the walls of the chamber. This confinement allows the plasma to reach the temperatures and densities necessary for nuclear fusion reactions to occur.
  • Tungsten diverters are critical components in fusion reactors, as they expel waste gases and impurities while enduring high surface heat loads. Earlier the Carbon diverters were used  but with the coming of tungsten diverters there is a 25% increase in Surface tempratures ultimately enhancing the reactor's operational capabilities. Tungsten has one of the highest melting points of all metals, making it capable of withstanding the intense heat generated in fusion reactions.
  • Artificial Sun: The term "artificial Sun" is often used to describe tokamak reactors because they replicate the conditions found in the Sun's core where nuclear fusion naturally occurs. By creating a controlled fusion reaction on Earth, scientists aim to unlock a nearly limitless source of clean energy that could help address the world's energy needs while reducing reliance on fossil fuels and mitigating climate change.
  • Hurdles: Nuclear fusion holds promise as a clean energy source, potentially addressing climate change by providing limitless energy without carbon emissions. However, commercializing fusion remains challenging, with significant engineering and scientific hurdles to overcome. 
    • Despite the progress made by projects like KSTAR and ITER, fusion energy's contribution to addressing the climate crisis is still a long-term goal. Nonetheless, continued advancements suggest fusion could play a role in a green energy mix in the latter half of the century.

Conclusion:

The success of the KSTAR project is significant not only for South Korea but also for the global fusion community. It provides invaluable data for projects like the International Thermonuclear Experimental Reactor (ITER), a multinational fusion megaproject in France. ITER aims to achieve its first plasma in 2025 and be fully operational by 2035, with tungsten divertors playing a crucial role.

Associated Concepts:

  • Nuclear fission: 
    • Nuclear fission is a process in which the nucleus of an atom splits into two or more smaller nuclei, along with the release of a large amount of energy. This process is typically triggered by the absorption of a neutron by a heavy nucleus, such as uranium-235 or plutonium-239. When a heavy nucleus undergoes fission, it releases a significant amount of energy in the form of kinetic energy of the fission fragments (the smaller nuclei produced), as well as in the form of gamma radiation and the kinetic energy of the neutrons that are released.
  • International Thermonuclear Experimental Reactor (ITER): 
    • The International Thermonuclear Experimental Reactor (ITER) is a major international nuclear fusion research and engineering project. It aims to demonstrate the feasibility of generating energy through nuclear fusion on a commercial scale. ITER is a collaborative effort of members of the European Union (EU), the United States, China, Russia, India, Japan, and South Korea, with its headquarters located in France. ITER's design is based on a concept known as magnetic confinement fusion, where the plasma is heated to temperatures exceeding 100 million degrees Celsius, allowing hydrogen isotopes to fuse and release energy.
  • Plasma: 
    • Plasma is often referred to as the fourth state of matter, distinct from solid, liquid, and gas. It is a state in which gas becomes ionized, meaning that some of its atoms or molecules lose or gain electrons, resulting in the presence of free electrons and positively charged ions. This ionization process gives plasma unique properties that distinguish it from other states of matter. Plasma is prevalent in nature, existing in phenomena like lightning, flames, and the ionosphere surrounding Earth.