It’s Time to Fall in Love with Nuclear Fusion—Again

Let’s indulge: Once fusion arrives, handmade suns could wipe out all human problems in a go.

If nuclear fission is associated with catastrophe, nuclear fusion is associated with delay and fraud. The joke about fusion, the synthesis of lab-grown stars, is that it’s always 10 years away. Or 20. Two lonely little isotopes, each with a pathetically low mass, are joined in holy electromagnetism in a massive artificial thunderclap. The remaining nucleus is smaller than the mass of the reacting nuclei, and the leftover mass is converted into light or heat by virtue of E = mc².

But what a utopia fusion seems to promise. Even with the jokes and equivocation and scams, it’s hard to be blasé about fusion’s stellar possibilities. So let’s indulge: Once fusion arrives, handmade suns, sources of unlimited clean energy, would—will—wipe out all human problems in a go. Our glorious pet stars, requiring only everyday hydrogen to whip up in a lab, won’t belch out carbon or radioactive waste. Instead they’ll exhale helium. Helium! That nonrenewable resource that’s already running low! Fusion, my friends, means not just infinite carbonless energy but more balloons.

Fusion will, of course, rescue the environment and decarbonize planet Earth in a cool afternoon. It will also—don’t stop me now—render irrelevant all the dead-eyed petroleum kleptocracies and trade wars and real wars waged in their name. When energy can be produced anywhere, with common household ingredients, authoritarian states will no longer derive despotic authority by accidents of geography, but will, whoosh, become secular democracies, the better to share fusion-reactor tips and tricks in happy glasnost and savor the collective joy and peace of a burning, flooding planet restored to tranquil shades of green and blue.

Even leaving aside the Shangri-la, fusion is exciting here and now. In December 2022—a solid century since physicists first identified fusion as the source of star power—American scientists at the National Ignition Facility in Livermore, California, where ignition is a way of life, had a breakthrough. They’d aimed 192 lasers at the inside of a pearl-sized gold can called a hohlraum, creating a radiation bath that heated up the outside of a peppercorn-sized spherical nubbin of hydrogen coated in diamond in the center of the little can.

Atoms flew off the nubbin, forcing it to implode at a speed of nearly 400 kilometers per second—about four times a bolt of lightning. This created 100 million-degree plasma under hundreds of billions of atmospheres of pressure—a gas so hot that electrons were freed from atomic nuclei. At 1:03 am on December 5, humanity hit the threshold for fusion ignition in a lab. The first flash of a handmade sun. Though it blinked out rather quickly, after less than 100 trillionths of a second, the reaction created 3.15 megajoules of energy when a mere 2.05 went in—a glorious 150 percent return on investment.

Somewhat discouragingly, the first thought of the US Department of Energy, which its publicity team spelled out in an admittedly cool sci-fi video, was that this fusion ignition could somehow “support” the government’s project to extend the lifespan of nuclear weapons. But never mind. With at least 30 private fusion companies across the world promising clean energy built on the Livermore breakthrough, the air is supercharged with Kennedy-era electrons of hope. According to a survey from the Fusion Industry Association, most of these companies believe fusion electricity will be on the grid by the 2030s. It’s time to fall in love with fusion as if we’ve never been hurt before.

But it’s always good to keep your wits about you when it comes to fusion promises. Whenever both paradise and vast riches are at hand, fraudsters make their move. On March 23, 1989, before an audience of feather-haired University of Utah students and at least one member of the presiding bishopric of the Church of Latter-Day Saints, electrochemists Stanley Pons and Martin Fleischmann declared—no peer-reviewed nothing in sight—that they had “established a sustained nuclear fusion reaction.” Holding up something that looked like a baby’s bottle with a pen in it, Pons told the room that they had driven deuterium into a metal rod at room temperature using garden-variety electrochemical techniques. Presto, they’d formed a new atom. “There is a considerable release of energy,” Pons said. “We’ve demonstrated that this could be sustained. In other words, much more energy is coming out than we’re putting in.”

OK, then.

Lest anyone doubt that these chemists (curious: not nuclear physicists) had really made their own atom, Pons assured the audience that he and Fleischmann had found nuclear reaction byproducts: evidence of fusion. What’s more, the heat generated by their tabletop experiment was attributable to those byproducts alone. It “cannot be explained by any chemical process that is known,” he said, with a note of irritation.

Almost immediately, other electrochemists aimed to replicate the results. They failed. Other (known) chemical processes seemed to be generating the heat. When Pons and Fleischmann published a paper at last, their work was savaged as a sham. They’d misrepresented their byproducts. The two men fled for France, where they worked for a Toyota research lab; they were never fined or even sidelined from science. But the abracadabra hypothesis of “cold fusion” came under a pall. Today, those who keep faith in it have formed a kind of aggrieved mini-cult. In the curious state of mind that anti-vax doctors are known for, the cold-fusion crew dug in, and its members now grouse about having been blackballed from elite journals and reputable conferences.

The latest Livermore discoveries are carefully described as hot fusion.

To those in whose dreams fused nuclei dance, the cold-hot distinction is consoling. The lukewarm nothingburger of the George H. W. Bush era seems worlds away from real fusion, the white-hot variety produced by Energy Secretary Jennifer Granholm’s avant-garde DOE. What’s a homemade sun without otherworldly heat?

The National Ignition Facility is a 10-story laser complex the width of three football fields, and its imposing size makes the Pons-Fleischmann tabletop charade even more laughable. And this time with fusion, the renowned physicists—including Tammy Ma, a plasma physicist; Annie Kritcher, an experimental physicist; and Kim Budil, a laser physicist and the director of the Lawrence Livermore National Laboratory—did not jump the gun with a prepublication press conference and set off a failed replication jam among peer scientists. Instead, for decades, scientists at the National Ignition Facility have been piling up papers, detailing most recently how ignition via fusion was possible (in August 2021) and then how it happened (in December 2022).

Along the way, statements to the media from LLNL have offered more science than prophecy. Kritcher, the lead designer of one of the 2021 experiments and first author on one of the resulting papers, explained how her team brought fusion to the threshold of fusion ignition. She concentrated not on grandiose promises but on the crucial challenge to anyone trying to fuse atomic nuclei: The laser energy must make it into the beams and hit the hydrogen target. One improvement? “Reducing the coasting-time with more efficient hohlraums compared to prior experiments was key in moving between the burning plasma and ignition regimes,” she said.

Heat, light, matter: It’s supremely satisfying when the most advanced technology on earth is also the most elemental. I’m here to enlist in this ignition regime, especially if it means the reign of nuclear fusion and the simultaneous twilight of carbon and kleptocracy. But you know me: I’m in anyway, even if the ignition regime is, for now, just an ongoing spark of hope that humans can still improve the world somehow by studying hot plasma and beaming lasers into gold cans.

It’s Time to Fall in Love with Nuclear Fusion—Again

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