Scientists and engineers at the Lawrence Livermore National Laboratory in California for the first time successfully produced more energy from a nuclear fusion reaction than the laser power needed to start it—reaching a key milestone in the 60-year effort to achieve “fusion ignition.” 

The U.S. Energy Dept, for which the lab is a key research arm, announced the result at a Dec. 13 press briefing—calling it a major scientific breakthrough that will advance national security and offer potential to produce power that is clean, carbon free and reliable—although that reality remains “a few decades” away, agency officials and scientists said.  

Achieving fusion ignition is the first step and opens the door to new scientific realms, but there are “very significant” hurdles in science and technology to reach commercialization, Lawrence Livermore Director Kimberly S. Budil said during the presentation. 

“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.  

The achievement was reached Dec. 5 when scientists used 192 high energy lasers pointed at a capsule the size of a peppercorn that contains deuterium and tritium that is heated to more than 3 million° C, said Jill Hruby, National Nuclear Security Administration head, noting that the activity briefly simulated the “conditions of a star.” 

Long Haul Research

Fusion is the process by which two light nuclei combine to form a single heavier nucleus, releasing a large amount of energy. The idea of using lasers to induce fusion in a laboratory began in the 1960s and is known as inertial confinement fusion. It began more than 60 years of research and development in lasers, optics, diagnostics, target fabrication, computer modeling and simulation and experimental design, DOE said in a statement.

Lawrence Livermore built a series of power lasers to create the National Ignition Facility, “the world’s largest and most energetic laser system,” DOE said. “[It] uses laser beams to create temperatures and pressures like those in the cores of stars and inside exploding nuclear weapons.” The facility, costing about $3.5 billion, began operating in 2009. It also operates to test thermonuclear explosions for military purposes.

The announced experiment surpassed the fusion threshold by delivering 2.05 megajoules of energy to the target that produced 3.15 megajoules of fusion energy output, demonstrating for the first time a fundamental science basis for inertial fusion energy and achieving the target energy gain of more than one. 

“For the first time it stayed hot enough that it ignited and produced more energy than it used,” said Marvin Adams, NNSA Deputy Administrator for Defense Programs. 

But a commercial power generating facility using the laser fusion approach would need much faster lasers that consume less energy, according to the officials. “There are very significant hurdles, not just in the science, but in technology,” Budil said, although noting that the federal experiment "was a necessary first step." 

While early fusion experiments were disappointing, last year they produced 70% as much energy as the laser energy input, with adjustments made to improve outcomes.

President Joe Biden’s goal to reach commercial viability of laser-based power will take public and private research and investment. Magnetic fusion technology is further along than the inertial confinement approach used at the federal lab. 

"The president has a decadal vision to get to a commercial fusion reactor in, obviously, 10 years," Energy Secretary Jennifer Granholm said. "So we've got to get to work, and this shows it can be done."

Fusion's Multiple Paths

Laser and magnetic confinement approaches have made advances in recent years and the achievement last week will benefit both, said Tammy Ma, who leads the lab’s Internal Fusion Energy Initiative. She said DOE will soon issue a report to provide a framework for laser fusion energy research that will "inevitably require participation from across the community,” including federal researchers, academia, start-up companies and public utilities.  

The longer running ITER fusion research effort in Europe, which will test reactions in a large torroidal magnetic chamber called a Tokamak, marked some energy producing milestones in early 2022, but it is a more expensive project with  any potential commercial viability also well into the future .

Sector observers see private fusion ventures more focused on commercial outcome in project designs. 

A nuclear fusion startup led by Commonwealth Fusion Systems and MIT’s Plasma Science and Fusion Center announced last year a major advance in magnet fusion technology that the team says could lead to the world’s first commercial fusion power reactor by the end of the decade. The researchers are building a compact fusion reactor, called SPARC, which is set for a test in 2025.

The startup, backed by private investors that include Microsoft founder Bill Gates and Jeff Bezos, Amazon executive chairman, now is building a $500-million nuclear fusion research-office complex

Investment in fusion startups totaled $2.3 billion in 2021, with more than $1 billion expected this year, said BloombergNEF.

Related to the federal effort, Steven Arndt and Craig Piercy, respective president and CEO of the American Nuclear Society, said in a statement that while the experiment "required much more energy to generate ... a laser and operate [it] as a whole, this is still an important milestone.”  

The result "confirms that breakeven is possible for fusion energy and is encouraging for other efforts in the United States and internationally that seek the same goal through different approaches," they said. "The fusion community is turning its attention to the engineering developments needed to harness this energy source.” 

Senate Majority Leader Chuck Schumer noted in a statement that this year’s National Defense Authorization Act includes $624 million for the Inertial Confinement Fusion program to build on the breakthrough. It is the “highest-ever authorization,” he said. 

DOE also closes on Dec. 15 applications for $50 million in initial research grants to fund private fusion developer designs for a utility-scale pilot plant of at least 50 MW, with winners then needing to meet rigorous engineering and scientific milestones to qualify for up to $415 million in added research funding, if that total is appropriated by Congress, said a report by E & E News. 

It said about 15 private fusion companies seek the pilot plant grants, sourcing the figure to advocacy group, the Fusion Industry Association, which added that developers could form partnerships with DOE national labs under the program.