Sun in a Bottle (18 page)

RAYLEIGH-TAYLOR INSTABILITY IN INERTIAL CONFINEMENT FUSION:
Use lasers or particles to bombard a pellet of fuel and small imperfections on the surface of the pellet quickly become large fingers that cool the fuel and prevent it from fusing properly.

It was almost as if the laser scientists were trying to invert a glass so carefully that the surface of the water inside wouldn’t ripple at all. This is an extraordinarily difficult task. Even the twenty-armed Shiva machine, heating the plasma from twenty different directions at once, wasn’t uniform enough to keep the Rayleigh-Taylor instabilities in check. The twenty pinpricks of laser light were far enough apart from one another that they would create hot spots in the target rather than heating it uniformly. The pellet would compress, getting hot and dense enough to induce a little bit of fusion, but before the reaction really got going, the Rayleigh-Taylor instability would take over. Tendrils would form. Instead of getting denser and hotter, the deuterium would squirt out.

The Livermore scientists tried everything they could to get the Rayleigh-Taylor problem under control. One method mimicked the Teller-Ulam design for the hydrogen bomb. Instead of using the lasers to push directly onto a dollop of deuterium, the new method did it indirectly. The pellet was ensconced at the center of a hollow cylinder known as a
hohlraum.
Instead of striking the pellet, the lasers struck the insides of the hohlraum. The hohlraum then radiated x-rays toward the pellet. This setup is known as indirect drive, and it helped ameliorate the problems with the instabilities.

DIRECT DRIVE VERSUS INDIRECT DRIVE:
In direct drive (left), laser beams shine directly on a pellet of fuel. Indirect drive (right), on the other hand, has laser light shining on a hohlraum, which evaporates and shines x-rays on the pellet.

But it didn’t do enough. Shiva, which had cost $25 million to build, only performed a fraction as well as its designers had hoped. It didn’t come close to producing as much energy from fusion as it took to run the lasers. Reaching breakeven was a much harder task than expected. The answer seemed within reach, though: just build a bigger Shiva, one with ten times the power, and ten times the price. By the beginning of the 1980s, Livermore was building a $200 million laser named Nova. Researchers there were confident Nova would finally take them to the promised land—igniting fusion fuel, producing more energy than it consumed. Once more, fusion scientists were about to have their faith severely tested.

The science of inertial confinement fusion was following the same trajectory as that of magnetic fusion. Early optimism in the 1950s led scientists to believe that plasmas could be confined and induced to fuse relatively easily. Cheap, million-dollar machines, they thought, would be able to do the job. But the plasma always seemed to wriggle out of control. Instability after instability made the magnetic bottles leak, and million-dollar machines turned into ten-million-dollar and hundred-million-dollar machines. Laser fusion began with similar optimism. Livermore’s scientists thought their first few lasers could get more energy out than they put in. But instabilities like Rayleigh-Taylor allowed the plasma to escape its confinement. Million-dollar lasers grew bigger and more expensive. Soon, laser fusion machines were as expensive as their magnetic counterparts.

Even today, decades later, these two approaches—magnetic fusion and inertial confinement fusion—remain the ways that most scientists are trying to bottle up a tiny sun. But both methods are extremely expensive, and both are plagued with instabilities that threaten to destroy the dream of unlimited fusion energy. Shiva’s failure occurred two decades after Homi J. Bhabha predicted that fusion power plants were twenty years away. Yet in the 1970s, and even into the 1980s, fusion scientists spoke of power plants as being thirty years away. After decades of research, the goal of fusion energy had become ten years more distant.

As fusion scientists built ever-bigger tokamaks and lasers for tens and hundreds of millions of dollars, outsiders began to wonder whether there was another cheaper, easier path to fusion energy. The stage was set for the biggest scientific debacle of modern times: cold fusion.

We are also human, and we need miracles, and hope they exist.

 

 

A
n intricately crafted glass mushroom on a metal pedestal, the two-foot-tall machine dominated the room—even when it wasn’t running. But when the operator twisted a dial and brought the BioCharger to life, everybody stopped to look. The helical glass coil at the top of the mushroom glowed red, and the whole machine throbbed with electricity. Tubes running up and down the mushroom’s stalk fluoresced with blue and red light. It crackled ominously as strands of violet lightning shimmied down the sides and dissipated into the air. As the crowd stood transfixed, the smiling operator turned the dial back and the machine died abruptly. The smell of ozone lingered in the air.

The BioCharger is a device that supposedly transmits healing energy directly into your body. Its inventor swears that the machine will help cure your thrush, fatigue, diarrhea, night sweats, frequent urination, colds, unrefreshed sleep, and almost anything else that ails you. The machine wouldn’t ordinarily be allowed anywhere near a scientific conference, but the BioCharger wasn’t out of place at this one. Neither was the device to test how much mercury was in your mouth to help diagnose the causes of your diseases, nor the presentation that discussed the “energy chair”: an ordinary white plastic lawn chair with a generator underneath. (“We used to call it the electric chair, but figured we had to change the name,” the presenter said.) The chair supposedly leaves you refreshed and energized after sitting in it. At an ordinary scientific gathering, such claims would be laughed out of the building. But the Second International Conference on Future Energy was no ordinary scientific conference.

Held in September 2006 on the outskirts of Washington, DC, the Conference on Future Energy was a celebration of sorts. Its convener, Thomas Valone, had recently won a long legal battle with his employer, the U.S. Patent and Trademark Office. Valone was a patent examiner who had, in his view, been fired for his belief in cold fusion. A year after being reinstated in his job (with back pay), Valone called a gathering of researchers together to, once again, explore the future of energy: a future that includes cold fusion.

Cold fusion had burst upon the world nearly two decades earlier and had long since been discredited by the mainstream scientific community. Yet today it still has a strong following, a core of true believers who think it will help humanity unleash unlimited power from fusing atoms. Plenty of reporters, government officials, and even scientists remain under its spell. The dream of unlimited energy through cold fusion is so powerful that for almost twenty years the faithful have been willing to risk ridicule and isolation to follow it.

 

 

The biggest scientific scandal of the twentieth century began on March 23, 1989. Two chemists at the University of Utah, Martin Fleischmann and Stanley Pons, told the world that they had tamed the power of fusion energy at room temperature, bottling up a miniature star in a little hunk of metal. The university’s press release was full of enthusiasm:

 

At the press conference, the president of the university, Chase Peterson, pronounced that the scientists’ discovery “ranks right up there with fire, with cultivation of plants, and with electricity.” Yet such a monumental achievement came in a small and homely package. When Pons and Fleischmann displayed slides of their “reactor,” goggle-eyed reporters were stunned. The apparatus was little more than a small glass beaker mounted in a dishpan. The claim rattled around the globe in a matter of hours, astonishing physicists and igniting a tremendous controversy. Over the next few weeks, skeptics expressed graver and graver doubts about the Utah chemists’ claims, but other laboratories seemed to confirm their findings: in Utah, Georgia, Texas, Italy, Hungary, the Soviet Union, and India. The story of cold fusion quickly became a knotty mess that, decades later, has yet to be untangled.

Most physicists were immediately skeptical of the chemists’ claim, and it is easy to understand why. Pons and Fleischmann were stating that they had caused deuterium nuclei to fuse in a little jar at room temperature. This seemed to contradict everything that physicists knew about nuclear fusion. Because the positively charged deuterium nuclei must slam into each other at very high speeds to fuse, it means that fusion tends to occur only when the deuterium is at a very high temperature and high pressure. This, of course, was why fusion scientists were spending hundreds of millions of dollars on lasers and magnets to heat and confine deuterium plasmas.

Pons and Fleischmann’s setup was supposedly making an end run around physics’ requirements for fusion. There was no attempt to heat the deuterium to millions of degrees or to compress it to high densities. The chemists merely took a little rod of palladium metal, plopped it in a jar full of deuterium-enriched water, and ran an electric current through it. Somehow, without the benefit of high temperature and high pressure, the deuterium atoms were fusing inside that metal.

Though cold fusion seemed ridiculous, physicists could not dismiss the idea out of hand. It was possible, if unlikely, that palladium metal could somehow force the deuterium nuclei into contact. Pons and Fleischmann could possibly have found a new and fortuitous physical effect that nobody had anticipated. It had happened before. In fact, it had happened before to Fleischmann.

In 1989, Fleischmann was a well-respected English chemist. He had been a key player in the field of electrochemistry, the study of chemical reactions that occur because of the influence of electric currents. He had made his name, in part, by discovering a useful physical effect that nobody had predicted—or, at first, believed. In the early 1970s, he used lasers to detect the presence of a minute amount of a chemical on a piece of silver, even though conventional wisdom said that his results were impossible. The chemical should have been all but undetectable by the technique he used. But Fleischmann was correct; he had done the seemingly impossible. He had unwittingly discovered an effect that would be called surface-enhanced Raman scattering, a phenomenon that is now used in a variety of sensitive chemical detectors. Conventional wisdom was wrong and Fleischmann was right.

The scientific community soon rewarded Fleischmann for his discovery. In the mid-1980s, he was made a Fellow of the Royal Society, the highest honor that Britain bestows upon its scientists. By the late 1980s, his reputation made him welcome at scientific institutions around the world. He spent most of his time hopping between laboratories at his home university in Southampton, the Harwell laboratory (of ZETA fame), and a lab at the University of Utah.

Stanley Pons was the chair of the University of Utah’s chemistry department, and the two had a long history together. Fleischmann had taken the younger Pons under his wing in the mid-1970s when Pons was at Southampton. Long after Pons moved back to the States the two kept working together. Fleischmann, the elder statesman, and Pons, the eager young experimentalist, made a good team, producing an enormous amount of research. Pons was particularly prolific. By the late 1980s, he was publishing several dozen papers per year. This was a huge output, and it could be argued that the frantic pace led to careless work. Indeed, over the years, Pons and Fleischmann had published some papers that seemed ludicrous—such as one that involved highly unlikely reactions of nonreactive gases—but the two still maintained a good reputation. This is part of the reason that cold fusion got so much attention. Pons and Fleischmann were established scientists; they were not no-name amateurs like Ronald Richter had been. So when they announced their cold-fusion results in 1989, even skeptical physicists took the claim seriously.