New Korean "artificial sun" KSTAR record: 20 seconds at 100 million degrees
The Korea Institute of Thermonuclear Energy (KEF) reported that the nuclear reactor KSTAR (Korea Superconducting Tokamak Advanced Research), or "artificial sun", was able to operate a record time of 20 seconds at a temperature of 100 million degrees. Scientists managed to increase the operating time of the reactor from the previous record - 8 seconds - more than doubled.
High temperatures are needed to recreate the thermonuclear reactions that occur on the Sun. For this, hydrogen isotopes are placed inside the reactor. They heat up, creating a plasma state in which ions and electrons are separated. The task of ions is to maintain a stable state at high temperatures. Before KSTAR, various devices could reach 100 million degrees and higher, but one of them could not maintain a stable plasma state for more than 10 seconds.
In its 2020 experiment, KSTAR improved the performance of the ITB (Internal Transport Barrier) mode, one of the plasma modes of operation developed last year that allowed the plasma to remain stable over an extended period of time.
“The technology required for long-term plasma operations at 100 million degrees is the key to realizing fusion energy. KSTAR's success in maintaining a high-temperature plasma for 20 seconds will be an important turning point in the race for a critical component of a commercial nuclear reactor in the future, ” said Xi-Woo Yun, director of KSTAR's Research Center at KEF.
Scientists will publish details of the experiment next spring. Testing at KSTAR will continue. The ultimate goal of scientists is to achieve by 2025 continuous work for 300 seconds at a plasma temperature above 100 million degrees.
"Artificial Sun" was developed in collaboration with Seoul National University (SNU) and Columbia University in the USA. The project was approved in 1995, but the first stage of the project was completed only in 2007. The first plasma was obtained in June 2008. In 2018, KSTAR reached a temperature of 100 million degrees for the first time. The running time was 1.5 seconds.