New record points to fusion’s potential

Scientists and engineers at the world-leading UK Atomic Energy Authority (UKAEA) Joint European Torus (JET) facility in Oxford have generated 59 MJ of sustained fusion energy over a five second period.

This result more than doubles UKAEA’s previous record, set in 1997, which achieved 22 MJ of heat over around four seconds by fusing atoms together.

The JET facility is designed to harness the energy of fusion; it is the largest and most powerful tokamak machine on Earth. Experts, students and staff from the Europe-wide EUROfusion consortium were involved in the project that reached temperatures ten times higher than that at the centre of the sun and used the same fuel mixture anticipated to be employed by commercial fusion energy powerplants.

Fusion involves fusing atoms of light elements such as hydrogen together at high temperatures to form helium, releasing bursts of energy in the process. It is the same reaction that generates heat in the core of stars.

JET is a principal testing ground for the International Thermonuclear Experimental Reactor (ITER) based in southern France. The €20bn international research mega-project aims to advance the scientific and technological feasibility of fusion energy. It is expected to start operating in 2025 but will not produce large amounts of power until 2035 at the earliest. There will be one more fusion test at JET’s reactor from mid-2022 until 2023 and then it will close.

Some regard fusion as an environmentally friendly solution to the world’s energy needs, albeit for the future. It produces no greenhouse gas emissions; less radioactive waste than nuclear fission; and can create a significant supply of electricity from abundant fuel sources.

But challenges still remain before fusion can become a viable energy source. More than three times as much energy went into fusing the atoms at JET than was produced by the reaction. Constructing reactors that can withstand the extremes of temperature and radiation produced by fusion is also difficult.

The latest experiments at JET are important for the viability of ITER. However, the technology remains decades away from meeting today’s energy needs. ‘Fusion takes a long time, it is complex, it is difficult,’ says Dr Athina Kappatou, who led part of the JET project. ‘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.’

Blend of computerised imagery and photography of JET
Source: EUROfusion media library