Comparison graph of performance of 100 million degree ultra high temperature plasma

experiments during 2019 campaign, compared to previous year

The KSTAR research center of the National Fusion Research Institute realized a high-performance plasma that maintains ion temperature of 97 million degrees on average, one of the most important operating conditions of nuclear fusion, through the KSTAR plasma experiment conducted from August 2019 to the end of February 2020.

KSTAR achieved 100 million-degree ultra-high temperature plasma operation (retention time of about 1.5 seconds), which is about 7 times the solar center temperature (15 million degrees) during the experiment in 2018 and the retention time was extended more than 5 times during the experiment in 2019.

In order to realize the nuclear fusion reaction that occurs in the sun, a state of ultra high temperature and high density, on Earth, fuel (deuterium, tritium) should be put into the nuclear fusion reactor to create a plasma state, separated into ion nuclei and electrons, and the ion temperature needs to be raised to an ultra high temperature of 100 million degrees or more. Maintaining such a high temperature plasma in a stable state for a long time so that the fusion reaction actively takes place is a key technology for commercializing fusion energy.

The achievement this time is a result of stably implementing the Internal Transport Barrier (ITB) mode, which is one of the next-generation plasma operation modes, by controlling the plasma shape and density and maintaining the ultra-high temperature for longer periods of time. In addition, technology to effectively heat the center of the plasma was applied to increase the efficiency of KSTAR heating devices, such as neutral particle beam heating devices.

In addition to this, KSTAR conducted experiments covering more than 80 topics during the campaign to resolve scientific difficulties surrounding ITER and fusion reactors to be built in the future, such as the development of high-performance operation scenarios and experiments on plasma disruption mitigation.

The achievement this time, and other KSTAR experimental results, will be revealed at the 28th IAEA Fusion Energy Conference, to be held in France in October this year.

Meanwhile, during the 2020 KSTAR campaign, which will start in August this year, experiments will be conducted to improve the performance and time duration of high-performance operation modes, including the ultra-high temperature operation of the superconducting tokamak, by securing additional heating devices and improving control technologies.