KTH Physics

Putting the Sun into a Box (Alfvén lecture)

by Dr G. F. Matthews (project leader ”ITER-like Wall Project” JET, Culham, England)

Europe/Stockholm
F2

F2

Description
Nuclear fusion powers the Sun and stars, and can potentially supply almost limitless energy on Earth. The Joint European Torus (JET) experiment near Oxford, England, can heat isotopes of hydrogen to the extreme temperatures required for them to fuse into helium. JET holds the world record for fusion energy production. A common question is "if you put the Sun in a box, how do you stop the sides from melting?". Materials often become a focus of attention as a technology approaches practical use, and this is exactly what is happening in fusion research. ITER, which is currently under construction, is twice the size of JET and is expected to produce 500 MW of fusion power. For ITER, a combination of tungsten and beryllium plasma-facing materials is chosen, and for the past year a similar configuration has been tested with JET's ITER-like Wall. Many valuable lessons have been learned on issues critical to ITER. These range from limiting the build-up of radioactive tritium (an isotope of hydrogen used as fuel) to avoiding melting. The results also show that the problem of achieving the necessary conditions for a high fusion reaction rate in the plasma centre cannot be separated from the problem of choosing the wall materials. This talk will cover the fusion background to JET's ITER-like Wall, its installation by remote handling robots, and a summary of key results.