Edging closer to unlimited clean energy? French fusion reactor's breakthrough

In France, a new landmark in nuclear fusion was set. The WEST fusion reactor achieved a remarkable feat by maintaining plasma at about 50 million degrees Celsius for six minutes. This advancement signals a step closer to harnessing a virtually unlimited energy source.

Nuclear fusion technology promises to transform our energy landscape. It involves the merger of atomic nuclei to produce energy. The French WEST fusion reactor, as National Geographic highlights, maintained plasma at a scorching temperature much higher than the Sun’s core, which is around 15 million degrees Celsius, for a significant duration.

This breakthrough was made by the team at Princeton Plasma Physics Laboratory. While setting a new record marks progress in nuclear fusion research, realizing power plants based on this technology is still years away. Achieving plasma stability for extended periods is essential for this dream to become a reality.

Nuclear fusion mimics the processes at the Sun's core. It combines hydrogen atoms into helium, releasing vast amounts of energy and surpassing atomic fission. Per National Geographic, a kilogram of fusion fuel—mainly a mix of the hydrogen isotopes deuterium and tritium—could produce energy fourteen million times greater than a kilogram of fossil fuels, all while being greenhouse gas emission-free. This positions nuclear fusion as a potential inexhaustible and clean energy source.

Luis Delgado-Aparicio, the head of advanced projects at PPPL, describes nuclear fusion as akin to creating an "artificial Sun on Earth." Achieving higher temperatures than those in the Sun's core is a formidable challenge due to lower pressure conditions on Earth, necessitating these extreme temperatures for fusion.

Sustaining the nuclear fusion reaction is daunting as it tends to extinguish quickly, particularly with any contamination in the fuel mix. It's also pivotal for the fusion process to last long enough to be energetically profitable, generating more energy than required for heating the plasma. Despite not reaching this milestone of excess energy production, the latest record improved energy output by 15% over previous attempts.

Tokamaks, donut-shaped fusion reactors, contain plasma by using a robust magnetic field. The choice of materials for the reactor walls is a significant aspect of their design.

The WEST reactor initially featured carbon walls due to its ease of handling but was later upgraded to tungsten in 2012 because carbon absorbed tritium from the fuel. Despite tungsten's benefits, it poses challenges by melting at high temperatures, which contaminates the plasma, leading to cooling and inhibiting nuclear reactions. Tungsten will also be implemented in portions of the ITER reactor, the most substantial experimental reactor currently under construction in southern France.

Researchers from PPPL have further refined diagnostic tools for better plasma temperature monitoring and detecting tungsten movement. This expertise will significantly benefit the ITER reactor's development.