|MIT Achieves Breakthrough in Nuclear Fusion|
Researchers operating fusion reactor experiments at MIT, along with partnered scientists in Brussels and the U.K., have developed a new type of nuclear fusion fuel that produces ten times as much energy from energized ions as previously achieved. The experiments with the new fusion fuel, which contains three types of ions—particles with an electric charge due to the loss or gain of an electron—were conducted in MIT's Alcator C-Mod tokamak, a magnetic confinement reactor that holds the records for highest magnetic field strength and highest plasma pressure in a fusion experiment.
The Alcator C-Mod conducted its final run in September 2016, but data from experiments in the tokamak device were recently analyzed, revealing a unique type of nuclear fusion fuel greatly increases ion energies within the plasma. The results were so encouraging that researchers operating the Joint European Torus (JET) in Oxfordshire, U.K., the largest operational magnetic confinement fusion experiment in the world, repeated the experiments and achieved the same increases in energy generation. A study detailing the findings was recently published in Nature Physics.
The key to increasing the efficiency of the nuclear fuel was to add in trace amounts of helium-3, a stable isotope of helium that only has one neutron rather than two. The nuclear fuel used in the Alcator C-Mod previously contained just two types of ions, deuterium and hydrogen. Deuterium, a stable isotope of hydrogen with one neutron in its nucleus—compared to common hydrogen which has no neutrons—accounts for about 95 percent of the fuel.