Nuclear fusion reactor reaches 100 million degrees Celsius

At #2, we look at how we are getting closer to nuclear fusion energy, one step at a time.
Ameya Paleja
The nuclear fusion reactor at Seoul National University
The nuclear fusion reactor at Seoul National University

Ibrahim Can/Interesting Engineering 

Researchers at the Korea Superconducting Tokamak Advanced Research (KSTAR) facility at Seoul National University (SNU) in South Korea achieved an important milestone in nuclear fusion energy. Temperatures in the nuclear fusion reactor built at the facility reached an excess of 100 million degrees Celsius for the first time.

The Sun at the center of our solar system is the best example of nuclear fusion energy available to us. At its core, the Sun is a nuclear reactor that combines hydrogen atoms to create helium and tremendous amounts of energy. At 15 million degrees Celsius, the core of the Sun provides the right environment where matter turns into plasma and hydrogen atoms fuse into helium.

Controlling plasma within the reactor

Scientists have been trying to replicate these conditions on Earth to create energy from nuclear fusion where there is no radioactive waste to worry about. However, the high-temperature plasma created inside nuclear fusion reactors needs to be contained so that it does not damage the chambers of the reactors.

This is number 2 in Interesting Engineering's series showcasing the best innovations of 2022. Check back to discover more about groundbreaking AI, unique solar panels, new 3D printing methods and much more.

Nuclear scientists have attempted to use magnetic fields to develop a sharp cutoff in pressure near the reactor wall. Called the edge transport barrier (ETB), this prevents the heat and plasma from touching the reactor wall.

An alternate method is called the internal transport barrier (ITB), where higher pressure is created near the center of the plasma. The researchers at SNU used a modification of this method to create a lower plasma density and boosted the plasma's core temperature to over 100 million degrees, a record in itself.

Nuclear fusion reactor reaches 100 million degrees Celsius
Nuclear fusion energy is closer than ever to reality

Before this attempt, both ETB and ITB were known to be unstable. However, on this occasion, the method demonstrated stability and after 30 seconds, the reactor had to be shut down due to hardware limitations.

What happens next?

While having achieved an important milestone, scientists are still not sure what exactly made it work. They attribute the success to fast-ion-regulated enhancement (FIRE) or energetic ions present at the core of the plasma for giving stability to the plasma.

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Apart from confirming the cause of the stability, the researchers are also working on replacing the carbon components of the inner walls of the reactor with tungsten, which is expected to help the reactor run for longer durations.

The questions of whether the methods are economically feasible remain unanswered, though, and it might be a few more years before we begin to address that end of nuclear fusion technology.

This is number 2 in Interesting Engineering's series showcasing the best innovations of 2022. Check back to discover more about groundbreaking AI, unique solar panels, new 3D printing methods and much more.