Nuclear fusion researchers in South Korea call it an "artificial sun"—but it burns much hotter than the real one. Scientists say the Korea Superconducting Tokamak Advanced Research reactor—the KSTAR—recently broke a record it set in 2021: It sustained plasma at 180 million degrees Fahrenheit, or 100 million degrees Celsius, for 48 seconds. The previous record was 31 seconds. The achievement marks another step forward in the quest to harness nuclear fusion, a potentially unlimited source of clean energy that involves fusing atoms together instead of splitting them.
- The reactor: KSTAR is a tokamak, which the Department of Energy describes as "a machine that confines a plasma using magnetic fields in a donut shape that scientists call a torus." It's the most common design for experimental fusion reactors.
- The hard part: Heating plasma to a temperature high enough to fuse hydrogen atoms is "the relatively easy part," according to LiveScience. It's more difficult to keep the unstable, incredibly hot plasma in place without wrecking the reactor. In a news release, scientists said they arrived at the new record after making "improvements in the performance of the plasma heating systems and advancements in high-temperature plasma operation and control techniques." Carbon "divertors" that extracted heat and impurities were replaced with tungsten ones.
- Why it burns so hot: KSTAR researchers are trying to recreate the conditions in which energy is produced in the core of the sun, which reaches temperatures of 27 million degrees Fahrenheit. The reactor needs to hit temperatures more than six times higher because it is operating without the immense pressure found in the hearts of stars, LiveScience reports.
- Next steps: Si-Woo Yoon, director of the KSTAR Research Center, says the goal is to heat plasma to 180 million degrees Fahrenheit for 300 seconds by 2026, CNN reports. Yoon says this is "a critical point" for scaling up fusion operations. Yoon says KSTAR research will aid the development of France's ITER, the world's biggest tokamak, and "advance the commercialization of fusion energy."
(A California lab has made
a separate breakthrough in fusion research.)
,
uBlock 
,
and
Ghostery 
)
