We’ve had nuclear fission reactors in operation all over the world for ages, but nuclear fusion always seems to be a decade or two away. While one cannot predict when we’ll reach the goal of sustained nuclear fusion, the cutting edge in test hardware is advancing at a rapid pace that makes us optimistic. Beginning as soon as this month and extending over a few years, we’re living through a very exciting time for nuclear fusion and plasma physics.
The Mega Ampere Spherical Tokamak (MAST) got a big upgrade to test a new cooled divertor design. JET (Joint European Torus) will be testing the deuterium-tritium fuel mixture that will be powering the ITER (the research project whose name began as an acronym for International Thermonuclear Experimental Reactor but has since been changed to just ITER). And the Wendelstein 7-X stellarator is coming back online with upgraded cooled divertors by next year.
Here the MAST Upgrade’s Super-X divertors have so far shown a ten-fold decrease in the temperature which the divertor is exposed to while carrying thermal energy out of the tokamak reactor. This means a divertor design and ultimately a fusion reactor that will last longer between maintenance sessions. On the stellarator side of things, Wendelstein 7-X’s new divertors may allow it to demonstrate the first continuous operation of a stellarator fusion reactor. Meanwhile, JET’s fuel experiments should allow us to test the deuterium-tritium fuel while ITER is working towards first plasma by 2025.