Korean researchers develop way to sustain nuclear fusion

Tech

Published: 08 Sep. 2022, 16:25

Korean researchers develop way to sustain nuclear fusion

Kstar, or the Korea Superconducting Tokamak Advanced Research, developed by the Korea Institute of Fusion Energy (KFE) in Daejeon [NEWS1]

Researchers from Seoul National University (SNU) and the Korea Institute of Fusion Energy (KFE) have developed a new way to sustain nuclear fusion for a long period of time.

The research was reported in a study titled “A sustained high-temperature fusion plasma regime facilitated by fast ions,” published in Nature on Thursday. The team includes SNU professors Na Yong-su and Park Sang-jin and KFE researcher Han Hyun-sun.

The research came as a result of analyzing the fusion reaction of the Korea Superconducting Tokamak Advanced Research (Kstar) reactor, a nuclear fusion reactor located in Daejeon built by the KFE in 2007, according to the team.

Fusion reaction is the process that powers stars and requires the reactor to maintain over 100 million degrees Celsius (180 million degrees Fahrenheit) for as long as it can in order to produce cheap, nearly pollution-free, stable power. Due to the technical difficulties in maintaining the high temperature needed to create a state of matter called plasma, no reactor in the world has been able to sustain a fusion reaction for longer than the 30 seconds that Kstar managed last year.

Kstar, or the Korea Superconducting Tokamak Advanced Research, developed by the Korea Institute of Fusion Energy (KFE) is being upgraded by technicians on Jan. 27, 2021, in Daejeon. [NEWS1]

A simulation image of H-mode, left, and the fast ion regulated enhancement mode (FIRE mode) shows that the higher temperature is concentrated in the core of the plasma in FIRE mode, compared to H-mode, where the edge of the plasma is heated up. [MINISTRY OF SCIENCE AND ICT]

Kstar and most other reactors around the world are operated in a high confinement mode (H-mode), developed by German researchers in 1982. This has enabled reactors to reach the current stage but has led to the plasma state to burst like balloons due to the high pressure that builds up on the edge of the matter.

The researchers found that allowing fast ions, or particles with high energy levels produced due to the temperature, to stabilize the turbulence within the plasma leads the plasma to heat up much faster than in H-mode. The new technique has been named fast ion regulated enhancement mode (FIRE mode).

“FIRE mode came as a work of creativity after analyzing the reasons for failing to achieve the desired results in experiments, proving that Korean fusion reaction research can be unique,” said Prof. Na in a press release.

“The super-high-temperature plasma operation was possible because Kstar was built to the finest level and thanks to the cooperation between schools and institutes in and outside of Korea.”

BY YOON SO-YEON [yoon.soyeon@joongang.co.kr]