In the wake of a series of recent experiments, European scientists are now closer than ever to recreating nuclear fusion, which powers the Sun and the stars, on Earth.
The Joint European Torus (JET), a magnetically confined plasma physics experiment sited in Oxfordshire, has witnessed a breakthrough in its 40-year old endeavour to extract nuclear fusion energy by forcing together two forms of hydrogen.
The energy output produced by JET may not be massive, but it provides strong support for the conviction that nuclear fusion can be replicated on our planet successfully via a particular machine. In the words of Dr. Joe Milnes, the head of operations at the JET reactor lab, “The JET experiments put us a step closer to fusion power. We’ve demonstrated that we can create a mini star inside of our machine and hold it there for five seconds and get high performance, which really takes us into a new realm.”
The energy output generated by JET’s recent experiments is more than double what was produced through similar efforts in 1997.
The JET breakthrough gives hope for the International Thermonuclear Experimental Reactor (ITER) experiment conducted at the moment in France – an internationally led endeavour projected to become the world’s largest magnetic confinement plasma physics experiment in the world by 2025. The experiment aims to recreate the fusion processes of the Sun.
Operating on the principle that energy is released through squeezing together atomic nuclei instead of separating them, fusion is produced in the Sun’s core through enormous gravitational pressure. Given the significantly lower pressure sustained on Earth, temperatures of more than 100 million Celsius are necessary to achieve fusion. Since no materials can resist contact with such high temperatures, scientists have designed a heated gas, or plasma, that is held within a magnetic field.
Efforts to produce fusion on Earth are particularly urgent at this juncture where the need for carbon-free energy is greater than ever. Fusion-based power plants would generate no greenhouse gases and only small amounts of radioactive waste.
There is, however, skepticism as to whether the recent breakthroughs into the production of fusion will result in its commercialisation imminently. As BBC science correspondent Jonathan Amos notes, “Fusion is not a solution to get us to 2050 net zero. This is a solution to power society in the second half of this century.”
Another obstacle to fusion production in the immediate future is the fact that lab fusion reactions consume more energy than they produce. JET can no longer operate because its electromagnets tend to get too hot, while ITER will need to rely on internally cooled magnets.
This challenge can be overcome in the future by scaling up the plasmas used, but this will take time, concerted efforts, and long-term commitment. Around 300 scientists or so are working for JET at the moment, while the EUROfusion consortium, partnered with ITER, consists of around 5,000 experts. Around a quarter of the scientists working for JET are at the early stages of their careers. As Dr. Athina Kappatou has pointed out, “Fusion takes a long time, it is complex, it is difficult. This is why we have to ensure that from one generation to the next, there are the scientists, there are the engineers and the technical staff who can take things forward.”
Apart from technical hindrances, Brexit poses another challenge to getting as many countries on board as possible. The UK may still be a member of EUROfusion, but it will need to affiliate itself with certain EU science programmes to get fully involved in ITER. It has been unable to do so thus far as a result of disputes over trading arrangements post Brexit.
The world is watching as the promise of a nuclear fusion future looms closer. It is likely that JET will be decommissioned after 2023, while ITER is planning on commencing its plasma experiments around 2025.
Image Credit: NASA
