Join fusion physicist Rosaria Villari from the ENEA Frascati centre in Italy in this video about the EUROfusion experiments she is heading on water activation as part of JET’s last deuterium-tritium campaign. This campaign offers a unique opportunity to study not just the plasma physics of fusion energy, but also the technological aspects of operating with the fuel that will power future fusion power plants.
Watch the video on YouTube here.
So what is water activation?
When fusion happens inside our tokamak device, it produces fast neutron particles. Those take the fusion energy outside of the magnetic cage where we keep the hot fuel, but they can also make the cooling water that flows past the components in the device unstable. That energy comes out again in the form of gamma radiation as the water flows through the cooling circuit.
And why is this important to study?
We want to know where in our facility those gamma rays are absorbed. The water returns to normal very quickly, which means you get a concentrated radiation load. We need to understand how and where to provide shielding, but also to understand if any materials like electronics, superconducting magnets or valves.
How does this impact the wider field of fusion?
Almost every fusion design uses water for cooling. Our experiments will let us improve our understanding and our predictive models, so that other facilities like future fusion power plants can use our work to optimise their own designs. Current models have big uncertainties and high safety factors, and if we can improve our understanding that could mean a significant impact on the cost and design efforts to protect sensitive systems.
Why here and now at JET?
JET is the most powerful fusion machine we have right now, and the only tokamak before ITER starts that can already operate with the fusion fuel mix for future fusion power plants. This third deuterium-tritium experimental campaign is a unique opportunity to study water activation under the conditions close to those in a real fusion power plant.
The best and only chance to study this phenomenon?
Yes, exactly. Until ITER starts, JET is the only facility where we can study the effect of using deuterium-tritium fuel on our plasma and our device. So we are all excited to do this experiment now!