KSTAR ( Korea Superconducting Tokamak Advanced Research ), a superconducting fusion device, also known as the ‘Korean artificial sun’, set the new world record by maintaining high temperature plasma for 20 seconds with ion temperature of more than 100 million degrees Celsius.
As reported this week, the KSTAR Research Center of the Korean Fusion Energy Institute (KFE), in a joint investigation with Seoul National University (SNU) and Columbia University of the United States, achieved continued operation of plasma for 20 seconds with an ion temperature above 100 million degrees, which is one of the core conditions of nuclear fusion in the KSTAR 2020 Plasma Campaign.
Thus, the 8-second plasma operating time span established during the 2019 campaign was extended by more than 2 times.
To recreate the fusion reactions that occur in the Sun of our system, hydrogen isotopes must be placed inside a fusion device like KSTAR to generate a plasma state where ions and electrons separate, and the ions must be heated and kept at high temperatures.
Until now, there have been other fusion devices that have briefly handled plasma at temperatures of 100 million degrees or more. None exceeded the barrier of maintaining operation for more than 10 seconds. It is the operating limit of the normal conduction device and it was difficult to maintain a stable plasma state in the fusion device at such high temperatures for a long time.
In its 2020 experiment – which took place at the end of last November – KSTAR improved the performance of the ‘internal transport barrier mode’ (ITB), one of the next generation plasma modes of operation developed last year and which managed to maintain the state of the plasma for a long period of time, exceeding the existing limits of ultra-high temperature plasma operation.
Director Si-Woo Yoon, KSTAR Research Center at KFE, explained: “The technologies required for 100 million long plasma operations are the key to the realization of fusion energy, and KSTAR’s success in maintaining of high-temperature plasma for 20 seconds will be a major turning point in the race to secure technologies for the long-term operation of high-throughput plasma, a critical component in the commercial nuclear fusion reactor of the future. ‘
KSTAR began operating the device last August and extended its experiments to just a couple of weeks ago, performing a total of 110 – including high-throughput plasma operation and plasma disruption mitigation experiments. More key results will be shared at the IAEA Fusion Energy Conference to be held in May 2021.
The ultimate goal of this device is to achieve 300-second continuous operation with an ion temperature above 100 million degrees by 2025.