A view from below of the RFX machine at the RFX Consortium, a scientific and technological research facility in the field of controlled thermonuclear fusion as a possible energy source

Dal Pozzolo

© Stefano Dal Pozzolo / Contrasto


What is the most powerful force in the universe? Romantics would say love, physicists would say strong interaction, namely the bond that holds the protons in an atom together, despite the electrostatic repulsion that tends to separate them. At the heart of stars, pressure and temperature allow two hydrogen nuclei to come so close that the interaction between them is strong enough to fuse them into a single helium atom with lower mass, releasing energy. Explaining E = mc2 , Einstein said: “Very small amounts of mass may be converted into a very large amount of energy”. This is how stars work. Can this mechanism be replicated on Earth? The wager is... yes.
The international ITER project, funded by the European Commission and currently under construction in France, aims to test the feasibility of the fusion of plasma, a gas ionised by deuterium and tritium, two isotopes of hydrogen, to obtain 10 times more energy than would be required to heat the plasma to 150 million degrees. Since we cannot bring the nuclei closer together as if we were inside a star, we have to raise the temperature by injecting high-speed ion beams to start the fusion process.
In the study of fusion, Padua and its university are at the forefront on the international scene. The first research began in 1958 and since 1996 the RFX Consortium has been working on the design and construction of a prototype injector for heating the plasma in ITER. Unfortunately, the timeframe is long. Fusion development projects assume it will not be used commercially until 2050 at the earliest. Fusion is not a daring gamble. Everyone recognises the ambitious goal, with major technical complexities to overcome, but an abundant energy source with no radioactive waste could become the legacy we leave our children and grandchildren.

Alberto Claudio Alvisi