Call it the shot heard ‘round the world.
The monumental, first-ever demonstration of fusion ignition by Lawrence Livermore National Laboratory’s (LLNL) National Ignition Facility (NIF) marks a potentially world-changing breakthrough for fusion energy and a key initial step in a decades-long quest for limitless clean energy, U.S. government officials and LLNL scientists said Tuesday.
At an historic press conference held at U.S. Department of Energy (DOE) headquarters in Washington, D.C., officials with DOE, the White House Office of Science and Technology Policy (OSTP), the National Nuclear Security Administration (NNSA) and LLNL announced that scientists performing an inertial confinement fusion (ICF) experiment at NIF just after 1 a.m. on Dec. 5 produced more energy from the self-sustaining fusion reaction than they put in to create the reaction: a condition known as ignition.
With members of Congress, dignitaries and national laboratory directors in attendance, speakers at the stunning announcement celebrated the achievement as the culmination of 60 years of exploration and experimentation in ICF by generations of scientists at LLNL and collaborators in industry, academia and other DOE national labs, including Los Alamos and Sandia. Officials from DOE and the OSTP congratulated researchers on the milestone and said replicating ignition in the lab could set the stage for fusion to someday become a viable clean-energy option.
“Last week, at the Lawrence Livermore National Laboratory in California, scientists at the National Ignition Facility achieved fusion ignition — creating more energy from fusion reactions than the energy used to start the process,” said DOE Secretary Jennifer M. Granholm. “It's the first time it has ever been done in a laboratory anywhere in the world — simply put, this is one of the most impressive scientific feats of the 21st century.”
Granholm added that the unprecedented accomplishment will strengthen national security and moves the world closer to the possibility of an abundant, carbon-free energy source for the future.
“It would be like adding a power drill to our toolbox for building a clean-energy economy,” Granholm said. “Today, we tell the world: America has achieved a tremendous scientific breakthrough — one that happened because we invested in our national labs and fundamental research. And tomorrow, we will continue to work toward a future powered in part by fusion energy.”
Earlier this year, DOE unveiled a 10-year strategy for developing commercial fusion energy that included a $50 million funding opportunity to support design of a pilot magnetic fusion plant. Granholm said experts are peer-reviewing applications and may have a decision by early next year.
In accomplishing one of the most complex scientific grand challenges of the last century and completing a long-awaited objective for NIF, officials and scientists confirmed that, for a fraction of a second, LLNL researchers produced 3.15 megajoules (MJ) of fusion energy output using 2.05 MJ of laser energy delivered to the target, demonstrating the fundamental science basis for inertial fusion energy. The results were peer-reviewed and verified by outside parties, scientists said.
Hailed by government officials as a watershed moment for fusion energy, the results are a “proof of concept” that a thermonuclear fusion reaction — the same reaction that powers the sun and stars — can be reproduced in the laboratory and result in a net energy gain, opening doors to a new scientific understanding of fusion and technological advancements in national defense and energy production, speakers said.
Following Granholm’s announcement, White House OSTP Director Arati Prabhakar described her brief experience as a summer student working on fusion research at LLNL in the 1970s and congratulated generations of scientists for overcoming decades of struggles and setbacks to accomplish a true “scientific milestone.”
“They never lost sight of this goaI and I think this is such a tremendous example of what perseverance really can achieve,” Prabhakar said. “It took so many different kinds of advances that ultimately came together to the point that we could replicate that fusion activity in this controllable way in a laboratory … The prospect [of fusion energy] now is one step closer in a really exciting way. This is an amazing example of the power of America's research and development enterprise.”
DOE Under Secretary for Nuclear Security and NNSA Administrator Jill Hruby said in achieving ignition, LLNL researchers have “opened a new chapter in NNSA’s science-based Stockpile Stewardship Program,” one that enables scientists to modernize nuclear weapons and explore new avenues of research in nuclear science.
"Unlocking ignition at NIF will allow us to probe the extreme conditions found at the center of nuclear explosions and address significant longstanding stewardship questions,” Hruby said. “The unprecedented nature of reaching ignition confirms what I and previous administrators of the NNSA have been saying for decades: there is no more dedicated or more talented group of scientists in the world. The tireless efforts of thousands of people from around the national security enterprise, and their predecessors are responsible for this breakthrough.”
Following Hruby, NNSA Deputy Administrator for Defense Programs Marvin “Marv” Adams showed a NIF target capsule and explained the science behind fusion reactions. Adams said ignition will enhance national security by helping NNSA maintain confidence in the nuclear deterrent, advance the country’s non-proliferation goals and increase national security.
“The achievement we celebrate today illustrates that big, important accomplishments often take longer and require more effort than originally thought,” Adams said. “And that these accomplishments are often more than worth the time and effort that they took.”
The press conference concluded with remarks from LLNL Director Kim Budil, who acknowledged that the pursuit of fusion has been an “incredibly ambitious goal” at the Lab, requiring the contributions of thousands of scientists over the years, including noted fusion pioneer and former Laboratory Director John Nuckolls.
Budil said ignition would not have been possible without a “long-term commitment of public investment in fusion science” and will serve to advance national security, demonstrate continued U.S. leadership in science and technology and generate “tremendous excitement in the fusion community,” particularly in the private sector.
“The science and technology challenges on the path to fusion energy are daunting but making the seemingly impossible possible is when we're at our very best,” Budil explained. “Ignition is a first step — a truly monumental one that sets the stage for a transformational decade in high energy density science and fusion research — and I cannot wait to see where it takes us.”
While optimism reigned for the event, Budil cautioned there are still “significant hurdles” and engineering challenges to solve before the commercialization of fusion energy becomes a reality, such as the ability to reproduce ignition many times per minute and making fusion reactions simpler and more efficient.
“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,” Budil said.
Officials and scientists thanked LLNL’s many collaborators on NIF and ICF research and DOE, NNSA and Congressional stakeholders.
Entering a new chapter for fusion energy
Following the press conference, a technical panel of NIF scientists convened to discuss details of the achievement and what ignition might mean for the future of fusion energy. NIF’s Program Director for Weapon Physics and Design Mark Herrmann moderated the panel, providing an overview of NIF and a play-by-play of the historic shot.
Herrmann said on Dec. 5, NIF scientists performed a NIF shot as they always do — firing the facility’s 192 powerful lasers onto a BB-sized target of deuterium and tritium (DT), heavier isotopes of hydrogen. However, in this experiment, the laser energy was upped to 2.05 MJ, and conditions of implosion symmetry, heat and compression were just right, generating the record-breaking energy output of 3.15 MJ.
“There's a race between heating and cooling and if that plasma gets a little bit hotter, the fusion reaction rate goes up, creating even more fusions, which gets even more hot — so the question is, can we win the race?” Hermann said. “For many decades, we lost the race, and we got more cooling out than we got the heating up, so we didn't get to this ignition event. But last Monday, that all changed, and we able were able to win the race and get very significant heating of the fusion plasma up to very high temperatures.”
Considered the “holy grail” of fusion energy research, ignition comes just over a year after NIF reached a then-record-setting 1.3 megajoule shot, which produced about 70 percent of the energy put into the experiment via fusion reaction, planting NIF firmly on the doorstep of the milestone.
Researchers attributed the success after previous near-misses to a combination of improvements in target design, better predictive modeling backed by machine learning and “cognitive simulation,” advances in laser capabilities and other adjustments.
Annie Kritcher, team lead for Integrated Modeling and the principal designer for the experiment, said the shot was part of a new NIF campaign that began in September, where the team introduced a new laser capability and a thicker capsule for the fusion fuel, providing more margin for achieving ignition. The team also made changes to improve implosion symmetry, which were fed to a cognitive simulation design team that determined there was high probability of a “yield gain of at least one,” Kritcher said.
Given the recent advancements and promising models, team members said they had “high hopes” and “good reasons to be optimistic” that the Dec. 5 shot would be extraordinary.
Arthur Pak, team lead for Stagnation Science, said that the team confirmed the net energy yield using multiple independent diagnostics to measure the number of neutrons that escaped the reaction, including radioactive decay and a magnetic spectrometer, giving them “high confidence” in the results.
Pak credited the breakthrough to the “tireless work of technicians and operators” that make observations of fusion plasma with improved diagnostics. Chief Engineer for the NIF Laser System Jean-Michel Di Nicola said the team stood “on the shoulders of multiple generations of optical, material and laser physicists who have designed and optimized ever-increasing performance in terms of laser delivery.” Principal Experimentalist Alex Zylstra, representing the experimental team, said the effort built on knowledge gained from a long history of previous experiments with specialized configurations and new diagnostics.
“All that work led up to a moment just after 1 a.m. last Monday when we took a shot and as the data started to come in, we saw the first indications that we'd produced more fusion energy from the laser inputs,” Zylstra said.
In addition to describing the behind-the-scenes work of the history-making shot to attendees and media, team members shared personal stories of hearing of the news of ignition later that morning.
Kritcher said she’d had “vivid dreams of possible outcomes” prior to the event and awoke to excited texts from Zylstra, informing her of ignition.
“You start looking and you see one diagnostic and you think, ‘well, maybe that's not real.’ And then you start to see more and more diagnostics, rolling and pointing to the same thing,” Kritcher said. “It was just a great feeling.”
Tammy Ma, who leads the Laboratory’s Inertial Fusion Energy (IFE) Institutional Initiative, said she was at the San Francisco International Airport waiting to board a plane for Washington when her phone rang.
“I got a call from my boss saying, ‘I think we got ignition,’ and I burst into tears,” Ma recalled. “I was jumping up and down in the waiting area — the crazy person. And yeah, the tears were streaming down my face.”
Looking to the future, Ma said ignition “lays the groundwork” for the feasibility of inertial fusion energy and creates a roadmap for reaching even higher energy gains and, potentially, a pathway to pilot commercial fusion plants in the coming decades.
“Developing an economically attractive approach to fusion energy is a grand scientific and engineering challenge — without a doubt, it will be a monumental undertaking,” Ma said. “However, the potential benefits are enormous; clean, carbon-free, abundant reliable energy capable of meeting the world's energy demands, and furthermore, providing for the energy sovereignty and energy security of the U.S.”
Ma said that an upcoming DOE Office of Fusion Energy report will set the framework for a new IFE program in the U.S., which is currently at a “divergent point” where more investments are needed to make the technology simpler and more efficient, and to determine the best design for fusion energy.
“Such a program will inevitably require participation from across the community, both the public sector but the private sector as well,” Ma said. “We look forward to working with the Department of Energy to leverage and capitalize on these great results for a fusion energy future. The time is now.”
As impressive as the ignition accomplishment is, researchers said they already have their sights set on future improvements for fusion experiments at NIF. Next summer, Di Nicola said, the team will design experiments and field shots with additional laser energy, providing them with more margins for ignition, and, with more investments, could produce even larger target gains. Target Fabrication Program Manager Michael Stadermann added that the target capsule used in the ignition shot had flaws, which was “very encouraging” for the team.
“This gives us confidence that we can make shells of equal quality and better quality in the future, and that we'll be able to reproduce this experiment or even improve on it,” Stadermann said.
Back in Livermore, the significance of the moment was not lost on the hundreds of Lab employees who watched the live, early-morning press conference as it was simulcast in several auditoriums across the main Lab site, with many viewers expressing pride in their co-workers and in the Lab’s continuing commitment to pushing the boundaries of science.
“It was very motivating, seeing scientific people at the highest level, including the White House science adviser [at the press conference]. It shows how impactful some of the work we do is and how it can shape the movement toward renewable energy,” said engineer Michael Kirby. “Also, our achievements are broadcast to the nation and the world, which is not something I thought I’d ever see.”
“There are very few moments in a generation where you have the opportunity to sit and watch science being made,” added Associate Program Leader Terri Stearman. “This is our moonshot. There will not be another opportunity to be with your fellows at 7 a.m. to watch your boss and all the great women on stage, unapologetically speaking about both themselves and those who came after them.”
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