This advance demonstrates the fundamental viability of fusion energy, something researchers have been pursuing since the 1950s. But this scientific experiment requires the world’s most powerful lasers and does not must be the immediately practical way to generate fusion power. More scientific and technical breakthroughs will be needed to make it happen Fusion from a lab experiment to a commercial technology can provide reliable, carbon-free power to the grid.
In fusion reactions, whether in a reactor or in the core of a star, atoms collide until they merge, releasing energy. The goal of fusion power is to extract more energy from the fusion reaction than is put in to power and keep the fuel in place, in a controlled manner. Until now, that has never been proven.
The fusion reaction at NIF has done just that, generating 3.15 megajoules of energy, more than the 2.05 megajoules provided by the lasers used in the reactor. Last year, the same facility produced about 70% of the energy that powers the laser reaction. The lasers need more power to run than they supply the reactor, but even seeing the net power gain in the system is an important milestone.
“This creates a lot of wind in the community’s sails,” says White Anne, dean of the nuclear science and engineering department at MIT. However, she added, that doesn’t mean we’ll see fusion power on the grid tomorrow: “it’s not realistic.”
The lab uses the world’s largest and most powerful laser in a fusion approach called inertial confinement.
Although inertial confinement was the first fusion scheme to produce a net energy gain, it is not the most likely route for any possible commercial fusion attempt. Magnetic confinement, specifically a donut-shaped reactor called a tokamak, is seen by many fusion scientists as the way forward.
The net gain seen in the inertial confinement experiment does not reverse other approaches to fusion energy, such as tokamak. The physics and techniques to get there are different between different concepts, says White.
