South Korea's 'Artificial Sun' Sustains Temperatures of 100 Million Degrees Celsius For 48 Seconds in Record-Breaking Feat

South Korea's very own nuclear fusion reactor was able to achieve a record-breaking feat of sustaining temperatures of 100 million degrees Celsius for 48 seconds.

South Korea's Artificial Sun Breaks Previous World Record

The artificial sun, or the Korea Superconducting Tokamak Advanced Research (KSTAR), broke its earlier world record of 31 seconds, which it also set in 2021. While the breakthrough may appear small, it is, nonetheless, a remarkable step towards the long journey to a source of clean energy that is close to unlimited.

Scientists behind the KSTAR aim to enable the reactor to sustain such record temperatures for up to 300 seconds in 2026.

Harnessing Nuclear Fusion Power

For over 70 years, scientists have been trying to find ways to harness nuclear fusion power. Through hydrogen atoms fusing to make helium in extremely high temperatures and pressures, the main-sequence stars end up turning matter into light and heat. This leads to the generation of enormous energy amounts without long-lasting radioactive waste or greenhouse gas production.

However, it is not easy to replicate the conditions present within the hearts of fiery stars. The most common fusion reactor design operates through plasma superheating and trapping this matter within a donut-shaped reactor chamber with strong magnetic fields.

However, the process of keeping the superheated and turbulent plasma coils in place for sufficient periods for nuclear fusion to happen has been quite painstaking. While the first tokamak was designed by Natan Yavlinksky, a Soviet scientist, in 1958, nobody has ever been able to make a reactor that can release more energy than what it takes in.

One of the biggest challenges comes with handling plasma that is sufficient enough for fusing. Since they need to work in lower pressures compared to the conditions where fusion naturally happens in star cores, fusion reactors need extremely high temperatures. In fact, the temperature requirements should be many times hotter compared to the Sun.

Though it has been relatively easy to superheat plasma in such temperatures, it has been tricky to find ways to corral it so that it would not burn through the reactor without breaking the process of fusion. This is typically done with magnetic fields or lasers.

In the case of KSTAR, the scientists wanted to extend the burning time of their plasma to exceed the reactor's previous record. To do so, they tweaked certain aspects of the design, such as replacing carbon for tungsten to boost the efficiency of the "divertors," which extract ash and heat from the fusion reactor.

Si-Woon Yoon, the director at the KSTAR Research Center, says that, though this is the first experiment conducted with the new tungsten divertor environment, thorough campaign preparation and hardware testing allowed them to see results that surpass the previous record of the KSTAR in a brief period.

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