There is not only the ITER project. The JET reactor has achieved major milestones in nuclear fusion

The need to develop new types of steel capable of being minimally activated by high-energy neutron impact, the importance of stabilising the plasma, controlling turbulence, etc., are just some of the challenges that nuclear fusion research projects must overcome before the first commercial reactors in this category can start operating.

The best-known project in this field is the IITER (International Thermonuclear Experimental Reactor). An experimental reactor which, when completed in Cadarache (France), will be the largest of its kind in the world. According to EUROfusion, a consortium of national research institutions from the European Union and Switzerland, which is funding the project, this will happen before 2030.

In this reactor, scientists confine charged deuterium and tritium nuclei using a magnetic field. What happens is that, no matter how powerful the field is, when the particles are produced, they take on a wide variety of energies, some of them very high, so if they exceed the energy containment limit of the field, they can escape. The problem is that if too many particles escape, a lot of energy is lost and the fusion reaction cannot be sustained over time. Ultimately, what scientists are aiming for is for the escaping energy to be small enough so that there is no decreasing energy level within the reaction.

For this reason, other projects study different aspects related to fusion, such as JET (Joint European Torus), an experimental fusion reactor, located in Oxford (England) and also financed by EUROfusion. This reactor has managed to solve this problem, although for a short time, mainly due to its size, since the larger it is (JET is 12 metres and ITER is 20 metres high), the better it can control small variations in magnetic fields and increase the amount of plasma.

It was expected that in 2023, after 40 years of operation, three test campaigns with ionised plasma containing deuterium and tritium nuclei, the participation of more than 300 scientists, and the acquisition of knowledge that would play a fundamental role in the development of reactors such as ITER, JET closed, but has surprised with a new milestone that has now become known, managing to produce 69.26 megajoules of energy during a 6-second pulse and using only 0.21 milligrams of fuel (the same as that used by ITER).

The end of JET has not meant that ITER is not alone in this journey, but are just two examples of many other projects such as JT-60 or JT-60SA.