JET, the Joint European Taurus, is currently the world’s largest fusion tokamak; on Tuesday the 6th of December, 15 of us were lucky enough to view this feat of engineering in person.
By the end of the century, it is estimated that our population may double whilst our energy usage is forecasted to triple, causing a critical demand for a safe and sustainable alternative to fossil fuels. So for 33 years, scientists at JET have been studying nuclear fusion, aiming eventually to design the conditions that will be required for a commercial nuclear fusion power plant.
Fusion is the nuclear reaction in which lighter nuclei join to form a heavier nucleus whilst releasing energy. To inspire JET, the scientists and engineers turned to a nuclear fusion reactor they knew was already in existence – our sun. The sun’s core reaches 15,000,000°C and is approximately 150 times denser than water; to mimic these conditions would be an incredible advance in science. At JET they have managed to heat the core of their tokamak to a temperature of 150,000,000°C, ten times that of our sun, thus compensating for not being able to match its extreme density. They have achieved this through a combination of radiofrequency heating and neutral beam injections of tritium (a super heavy isotope of hydrogen) into the tokamak. The extreme heat causes the deuterium-tritium fuel mix to become plasma – the state beyond gas. The plasma is conductive and thus able to be magnetically confined in a torus shape. This combination of features provides the conditions for the fuel to fuse and release energy.
So far the energy required to reach the conditions needed at JET outweighs the energy which is released by the fusion, however, JET remains at the forefront of nuclear fusion research. Currently JET carries out experiments to assist with the construction and design of ITER, a new nuclear fusion tokamak under construction in Provence, in the South of France. This is a collaboration and endeavour of 35 nations, and it is hoped that by 2050 we will be able to efficiently generate nuclear energy in order for it to be available to a consumer market.
We would like to thank the science department and teachers who made this trip possible; it was both eye-opening and enjoyable.