Physics World (, an international monthly magazine published by the Institute of Physics, has named the National Ignition Facility’s (NIF) achievement of fuel gain one of its top 10 breakthroughs of the year.
Ignition — the process of releasing fusion energy equal to or greater than the amount of energy used to confine the fuel — has long been considered the “holy grail” of inertial confinement fusion science. Before achieving ignition, a key step along the path is to have “fuel gains” greater than unity, where the energy generated through fusion reactions exceeds the amount of energy deposited into the fusion fuel and alpha-particle self-heating of the fusing region.
NIF — the world’s largest and most energetic laser — was the first facility to ever reach the milestone of achieving fuel gains greater than 1 with significant levels of alpha-heating. In a paper published in the Feb. 12 online issue of the journal Nature, scientists detailed a series of experiments conducted on NIF, which showed an order of magnitude improvement in yield performance over past experiments.
“Creating the conditions for sustained nuclear fusion to occur in the laboratory has proved notoriously challenging, but persevering is essential because success could lead to safe and clean sources of energy,” said Hamish Johnston, editor of physicsworld.com. “By obtaining a fuel gain of greater than one, the team working at the National Ignition Facility has taken an important step toward realizing fusion energy.”