Fusion reactor designs with ‘long legs’ show promise

A recent assessment of the power handling capabilities of long-leg divertor configurations was performed and compared to conventional configurations using an edge plasma simulation code that could handle magnetic x-points in the leg. The combined effects of long-leg magnetic geometry, enhanced gas-plasma interactions and the presence of a secondary magnetic x-point are found to increase the peak power handling ability by up to a factor of 10 compared to conventional divertors — an unprecedented result.