Physicists with the National Ignition Facility at Lawrence Livermore National Laboratory have successfully produced a nuclear fusion reaction resulting in a net energy gain.
To create fusion ignition, NIF’s laser energy is converted into X-rays inside the hohlraum, which then compress a fuel capsule until it implodes, creating a high temperature, high pressure plasma. Image credit: National Ignition Facility, Lawrence Livermore National Laboratory.
Nuclear fusion is the process by which two light nuclei combine to form a single heavier nucleus, releasing a large amount of energy.
Our Sun generates its energy by nuclear fusion of hydrogen nuclei into helium. Duplicating this process is considered the ‘holy grail’ of fusion research — a dream physicists have been chasing since the 1950s.
There are two main routes to nuclear fusion: (i) magnetic confinement fusion that contains extremely high temperature nuclei in a magnetic bottle; and (ii) inertial confinement fusion that uses high power lasers to blast together nuclei in a miniature hydrogen bomb.
To pursue the second concept, Lawrence Livermore National Laboratory (LLNL) built a series of increasingly powerful laser systems, leading to the creation of the National Ignition Facility (NIF), the world’s largest and most energetic laser system.
NIF is the size of a sports stadium and uses powerful laser beams to create temperatures and pressures like those in the cores of stars and giant planets, and inside exploding nuclear weapons.
On December 5, 2022, a team of physicists at NIF conducted the first controlled fusion experiment in history to reach energy breakeven, meaning it produced more energy from fusion than the laser energy used to drive it.
The experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy.
“The pursuit of fusion ignition in the laboratory is one of the most significant scientific challenges ever tackled by humanity, and achieving it is a triumph of science, engineering, and most of all, people,” said LLNL Director Dr. Kim Budil.
“Crossing this threshold is the vision that has driven 60 years of dedicated pursuit — a continual process of learning, building, expanding knowledge and capability, and then finding ways to overcome the new challenges that emerged.”
“These are the problems that the U.S. national laboratories were created to solve.”
“This is a landmark achievement for the researchers and staff at NIF who have dedicated their careers to seeing fusion ignition become a reality, and this milestone will undoubtedly spark even more discovery,” said U.S. Secretary of Energy Jennifer M. Granholm.
“We have had a theoretical understanding of fusion for over a century, but the journey from knowing to doing can be long and arduous. Today’s milestone shows what we can do with perseverance,” added Dr. Arati Prabhakar, the President’s chief adviser for Science and Technology and director of the White House Office of Science and Technology Policy.
“This astonishing scientific advance puts us on the precipice of a future no longer reliant on fossil fuels but instead powered by new clean fusion energy,” said U.S. Senate Majority Leader Charles Schumer.
