Korea’s “artificial sun” facility has just been outfitted with some equipment that may allow it to generate high-temperature plasma above 100 million degrees Celsius (180 million degrees Fahrenheit) for even longer periods.

The Korean Superconducting Tokamak Advanced Research (KSTAR) is an experimental device located in Daejeon, South Korea. Its mission is to provide the incredibly hot conditions that would be required for sustained nuclear fusion, a powerful process that burns inside the Sun and other stars.

The KSTAR device “heats” these ultra-high temperatures using a tokamak, a large doughnut-shaped reactor that can utilize plasma, a hot charged gas made up of positive ions and free-moving electrons.

The artificial sun first reached 100 million degrees Celsius in 2018, which it maintained for just 1.5 seconds. That time was increased to 8 seconds in 2019, then a full 20 seconds in 2020. Its latest record, achieved in 2022, allowed it to maintain 100 million degrees Celsius for 30 seconds.

More recently, the device has been fitted with a number of new upgrades that may allow it to maintain this mind-blowing temperature for even longer. In general, the upgrades included replacing the carbon diverter with another made of tungsten, a material that boasts a high melting point and other desirable qualities.

Experiments using the new medium with the tungsten diverter will continue through February 2024. With this new equipment, the team now aims to reach 300 seconds by the end of 2026.

Nuclear fusion occurs when two light atomic nuclei combine to form a heavier nucleus, releasing enormous amounts of energy in the process. Theoretically, the enormous energy can be used to produce an almost unlimited amount of electricity.

This is the process that underlies the largest thermonuclear device in our solar system: the Sun. However, unlike the center of stars, the plasma on Earth requires extremely high temperatures to achieve nuclear fusion because it is not compressed by gravity.

Such high temperatures are required to provide the nuclei with enough energy to overcome their mutual electrical repulsion. Plasma also needs to be restrained by strong magnetic fields. As you can no doubt imagine, creating such conditions for long periods of time is no easy task.

However, that doesn’t stop scientists around the world who are understandably eager to master nuclear fusion. In France, teams of engineers and scientists are currently assembling the International Thermonuclear Experimental Reactor (ITER), the world’s largest fusion experiment. Recent updates to KSTAR will further expand our knowledge of nuclear fusion and will eventually be used in ITER experiments.