Revolutionary fusion advance achieved
Livermore looks nothing like the center of the sun, but this East Bay city, surrounded by vineyards and ranches, is where scientists have re-created the production of energy the way the sun does: through nuclear fusion.
On Tuesday, federal officials announced that Lawrence Livermore National Lab had achieved a historic breakthrough in its fusion research — creating a brief reaction that generated more energy than it consumed.
The long-elusive achievement, called “ignition,” brings the world one step closer to the goal of harnessing the same process that powers the sun to create safe, cheap, carbon-free electricity on Earth.
It comes at a time when the world is faced with soaring energy prices and a crisis of rising global temperatures caused by the use of fossil fuels.
“This is such a tremendous example of what perseverance really can achieve,” said White House Office of Science and Technology Policy Director Arati Prabhakar, in a Tuesday morning news conference in Washington D.C.
“It’s a scientific milestone. But it’s also an engineering marvel beyond belief,” she said. With both sides learning from each other, “this is how we do really big hard things.”
Addressing a global audience, Lawrence Livermore National Lab director Kim Budil praised her team and lab partners “who ensured that we could reach this moment, even when the going was tough. Over the past 60 years, thousands of people have contributed to this endeavor, and it took real vision to get us here.”
The experiment was conducted at the lab’s $3.5 billion National Ignition Facility, the size of three football fields. Scientists produce powerful reactions by smashing together — or fusing — hydrogen atoms into helium, using lasers.
The lasers generate intense pressure and heat, causing a rocket-like implosion that creates more than double the pressure at the core of the sun and sends temperatures soaring to more than 150 million degrees Fahrenheit, just like the sun, releasing a massive amount of
energy.
Just after 1:03 a.m. Dec. 5, the energy output of this reaction surpassed the input. National Ignition Facility’s lasers used 2.05 megajoules of energy from the grid, and generated 3.15 megajoules — a 53% increase.
The future hope is to build commercial reactors that could maintain this fusion without injecting heat — and create electricity that is cheaper and far cleaner than that from natural gas or coal. In recent years, the urgent need to find new energy solutions to combat climate change has accelerated the race toward nuclear fusion.
“We have taken the first tentative steps toward a clean energy source that could revolutionize the world,” said Jill Hruby, Under Secretary for Nuclear Security and National Nuclear Security, in a Tuesday morning news conference.
That is within reach, but is not yet practical, said lab director Budil. The National Ignition Facility is a scientific demonstration facility, with different considerations than a commercial fusion power plant. Decades of research may be needed to create commercial reactors that are affordable and self-sustaining, capable of keeping themselves going in controlled circumstances, to produce fuel.
Members of the research team said that news of the early morning breakthrough — through phone calls and texts — was thrilling.
“I got a call from my boss, saying ‘I think we got ignition,’ and I burst into tears,” said Tammy Ma, a plasma physicist at the National Ignition Facility. Waiting for a flight at San Francisco International Airport, “I was jumping up and down in the waiting area — that crazy person.”
But as late as Monday, physicists weren’t running around the facility shouting ”Eureka!” On the contrary, they remained silently glued to computers and the monitoring equipment, while the results were still being analyzed.
Even as news of the success leaked from the lab to the physics community, then the global media, the lab remained hushed.
“Our analysis is still ongoing,” said lab spokesperson Anne Stark on Monday.
During the past week, explained Budil, the Ignition Facility brought in members of the research team and external experts to Livermore to verify the data.
“It turns out that when you ignite…it’s unambiguous that something big happened,” she said. Before releasing the numbers, “it was important that we tell you the facts and that we get them right before we go public.”
Since World War II, scientists have dreamed that fusion might one day be exploited to create dependable electric power, with no carbon emissions or radioactive meltdowns or waste.
It’s a process that is constantly underway in the core of the sun. where high temperatures and extreme pressures fuse 500 million metric tons of hydrogen each second.
But here on Earth, until now it’s been an unfathomable process to replicate and control. The possibility captured the public imagination with the first public fusion demonstration at a General Electric exhibit at the 1964 World’s Fair, but its complexity derailed hundreds of subsequent projects, both private and public. Slowly, over time, scientists have improved tools and techniques.
The lab’s National Ignition Facility, founded in 2009, is the ideal place to undertake such an endeavor.
The facility was conceived to study fission, another nuclear process, used in nuclear weapons. Part of the nation’s Nuclear Security Administration’s Stockpile Stewardship Program, the facility offers a safe way to study the operation of modern nuclear weapons. Underground testing is now off-limits.
Such research can be conducted within the facility’s high-pressure conditions inside the controlled environment. Its experiments use extremely tiny amounts of test material — barely visible to the naked eye — and are safe.
Fission, fusion is a nuclear process.
But the two processes are quite different. Fusion is the joining of atomic nuclei; fission is the splitting of atomic nuclei. Fusion produces far more energy than that created by fission. And fusion, unlike fission, does not create harmful radioactive byproducts that need to be stored for thousands of years
The Livermore facility’s success is due to its creation of the world’s most precise and reproducible laser system.
Nearly 200 powerful laser beams are focused and fire simultaneously onto two sides of a metal cylinder about the size of a pencil eraser.
In a powerful multistep process, extreme heat and pressure cause two forms of hydrogen atoms to fuse into helium and release high-energy neutrons and other forms of energy in a controlled thermonuclear reaction.
In a fraction of a nanosecond — about a billion times faster than the blink of an eye — the lab generated a huge amount of ultraviolet energy and 500 trillion watts of peak power, enough to light 5 trillion hundred-watt bulbs.
“Any one thing going wrong can be enough to prevent ignition,” said team member and experimental physicist Alex Zylstra. “Everything has to be right. So we really have to sweat the small stuff.”
In recent years, the facility has continuously increased the experiment’s energy and power. In August 2021, an experiment made a significant step toward ignition, achieving an energy yield of more than 1.3 megajoules. This advancement put researchers at the threshold of fusion ignition.
The design of this experiment was modified, and an improved project was conducted last September.
“Going forward, we know we will make further breakthroughs. We’ll have further setbacks,” said Prabhakar. “But all of this is in the interest of promoting national security, pushing toward a clean energy future and redefining redefining the boundaries of what’s possible.