Scientists at Lawrence Livermore National Laboratory (LLNL) reached a major accomplishment last week in fusion ignition, which officials said will pave the way for advancements in national defense and the future of clean energy.
On Dec. 5, the National Ignition Facility (NIF) at LLNL successfully conducted the first controlled fusion experiment in history to reach this milestone -- also known as scientific energy breakeven, meaning it produced more energy from fusion than the laser energy used to drive it.
"We took a shot just after 1 a.m. last Monday and as the data started to come in, we saw the first indications that we had produced more fusion energy than the laser input," said Alex Zylstra, the principal experimentalist for the project. He also noted that the fusion work that the current team is doing is built on the many years of effort and research put in by their predecessors.
In addition to providing unprecedented capability to support the National Nuclear Security Administration (NNSA) Stockpile Stewardship Program, fusion ignition's potential for clean fusion energy could be a game-changer for efforts to achieve President Joe Biden’s goal of a net-zero carbon economy.
"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 Kim Budil in a statement.
"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,” she added.
The U.S. Department of Energy (DOE) and the NNSA held a press conference Tuesday announcing the historical feat along with Budil and the team of LLNL experts behind the experiment.
"The people at Lawrence Livermore National Laboratory's National Ignition Facility reached this ignition milestone because of the work others did before them, their analysis of data and models, their continued pursuit to have the best possible facility and their sheer excellence and grit," said NNSA Administrator Jill Hruby during the announcement.
Many scientists over the years have worked toward achieving this breakthrough since the 1960s when a group of LLNL scientists hypothesized that lasers could be used to induce fusion in a laboratory setting. Led by physicist John Nuckolls -- who later served as LLNL director from 1988 to 1994 -- this revolutionary idea became inertial confinement fusion, kicking off more than six decades of research and development in lasers, optics, diagnostics, target fabrication, computer modeling and simulation and experimental design, according to LLNL officials.
To pursue this concept, LLNL built a series of increasingly powerful laser systems, leading to the creation of 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.
Among those who previously worked to reach fusion ignition at LLNL is Arati Prabhakar, the President’s chief adviser for science and technology and director of the White House Office of Science and Technology Policy.
"It was 1978, I was a summer student in the middle of my college years, a 19-year-old kid and I got the chance to go work at Lawrence Livermore National Laboratory," Prabhakar recalled during Tuesday's press conference. She continued, "I show up and they give me a laser to work on and I said, 'This is cool. I like lasers but what's this laser all about?' and they said, 'We think that if you point enough lasers at a pellet of fuel, we want to see if we can get more energy released from fusion than the amount of energy that the laser's delivering to that pellet.'"
Prabhakar said she spent the entire summer working on the project and then went on to do other unrelated things but she kept an eye on what was going on at LLNL as they continued to pursue fusion ignition for many more years until finally accomplishing it last week. "I just think this is such a tremendous example of what perseverance really can achieve," she said.
Fusion is the process by which two light nuclei combine to form a single heavier nucleus, releasing a large amount of energy, according to LLNL officials. To create fusion ignition, 192 laser beams delivered more than 2 million joules of ultraviolet energy to a tiny fuel pellet.
"Fusion is an essential process in modern nuclear weapons and fusion also has the potential for abundant clean energy," said NNSA Deputy Administrator for Defense Programs Marvin "Marv" Adams.
LLNL’s milestone experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy from the laser 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 (IFE).
Many advanced science and technology developments are still needed to achieve simple, affordable IFE to power homes and businesses, and the DOE is currently restarting a broad-based, coordinated IFE program in the U.S. Combined with private-sector investment, there is a lot of momentum to drive rapid progress toward fusion commercialization.
However, Budil noted during Tuesday's press conference that while this experiment was a very critical first step, commercialization is still a number of years away.
"This is one igniting capsule, one time and to realize commercial fusion energy you have to do many things. You have to be able to produce many, many fusion ignition events per minute and you have to have a robust system of drivers to enable that," Budil said, adding that it probably won't be another six decades.
"I think it's moving into the foreground and probably with concerted effort and investment, a few decades of research on the underlying technologies could put us in a position to build a power plant," she said.
In the days since making the breakthrough, Budil said the team was analyzing all of the data and diagnostics to make sure all of the numbers were correct before announcing the historical feat. "It's really important that we tell you the facts and that we get them right before we go public," she said.
U.S. Rep. Eric Swalwell (D-Livermore) praised LLNL's accomplishment in a statement and pledged to continue pursuing funding toward the Lab's fusion work.
"I am thrilled that NIF -- the United States’ most cutting-edge nuclear research facility -- has achieved fusion ignition, potentially providing for a new clean and sustainable energy source in the future. This breakthrough will ensure the safety and reliability of our nuclear stockpile, open new frontiers in science, and enable progress toward new ways to power our homes and offices in future decades," Swalwell said.
"I commend the scientists and researchers for their hard work and dedication that led to this monumental scientific achievement, and I will continue to push for robust funding for NIF to support advancements in fusion research," he added.