Recently I posted a blog about futurist Stewart Brand's belief that environmentalists would come to embrace nuclear power over the coming decades [Natural or Manmade Environmentalism?]. The biggest challenge with nuclear power is how to deal with radioactive waste. One answer could be a fusion reactor that uses non-radioactive boron. Skeptics might think this sounds a lot like the promise of cold fusion, but there have been some successes that show this is a promising path to pursue. The U.S. Navy, however, recently shutdown the program ["Fighting for Fusion: Why the U.S. Isn't Funding a Promising Energy Technology," by William Matthews, Defense News, 5 March 2007]. Matthews' article discusses the work of physicist Robert Bussard, whose work was quietly funded by the U.S. Navy for eleven years. His work was showing progress when the plug was pulled.
"On Nov. 11, 2005, the day his small fusion reactor exploded in a shower of sparks and metal fragments, even physicist Robert Bussard didn’t know what he had achieved. ... Bussard’s research [involved] ... a small project with a very large goal: deriving usable energy from controlled nuclear fusion. Funding ran out at the end of 2005 and Bussard was supposed to spend the tail end of the year shutting down his lab. He kept postponing that in an effort to finish a final set of experiments. He completed low-power tests in September and October and began high-power testing of the reactor in November. After four tests Nov. 9 and 10, an electromagnetic coil short-circuited as electricity surged through it, 'vaporizing' part of his reactor, Bussard said, and bringing his tests to an end. 'The following Monday, we started to tear the lab down. Nobody had time to reduce the data that was stored on the computer. It wasn’t until early December that we reduced the data and looked at it and realized what we had done,' he said. Bussard said he and his small team of scientists had proven that nuclear fusion can be harnessed as a usable source of cheap, clean energy."
According to Matthews, Bussard, who is aging and in ill health, claims he has been unable to generate interest in reviving his work in no small part because "the U.S. Energy Department has a competing project, and has spent five decades and $18 billion on an as-yet-unsuccessful effort to solve the fusion puzzle." To be fair, skeptics always become wary anytime someone claims to have solved a problem that thousands of other very smart people have failed to solve. Generally, if it seems to good to be true, it probably is. The debacle with cold fusion still lingers in memories of most scientists. This may be different, however. Don Gay, a former Navy electronics engineer who helped keep Bussard's project alive, and others insist that Bussard truly has solved the fusion puzzle. This is not Bussard's first innovative foray.
"In 1960, he developed — on paper — the Bussard ramjet, an engine designed to power space vehicles by collecting hydrogen atoms from the near-vacuum of space and feeding them into a fusion reactor. His idea was the basis for the 'Bussard collectors' that powered the fictional space ships in the 1960s television series 'Star Trek.' A decade later, Bussard served as assistant director of the Thermonuclear Reaction Division of the now defunct U.S. Atomic Energy Commission. He also worked for U.S. government nuclear laboratories at Los Alamos, N.M., and Oak Ridge, Tenn., and for TRW Systems. Along the way, Bussard founded his own small company, Energy Matter Conversion Corp. — EMC2 — to pursue research into fusion. Bussard aims to use fusion to produce cheap, inexhaustible, clean energy. Unlike other forms of nuclear energy, including other methods of fusion, Bussard’s process does not produce radioactivity."
"His fuel of choice is one of the earth's most common and least exotic elements: boron. It can be scooped from the Mojave Desert in California, possibly even extracted from sea water. Boron is used in the production of hundreds of products as diverse as flame retardants, electronic flat panel displays and eye drops. It's so common that no country, company or individual could corner the market on the fuel supply, Gay said. The process Bussard hopes to perfect would use boron-11, the most common form of the element. Bussard says his experiments — which achieved fusion with deuterium, not boron — in November 2005 proved that the boron process will work. The boron reactor would be similar to, but more powerful than, the reactor that blew up in 2005. Bussard's reactor design is built upon six shiny metal rings joined to form a cube — one ring per side. Each ring, about a yard in diameter, contain copper wires wound into an electromagnet. The reactor operates inside a vacuum chamber. When energized, the cube of electromagnets creates a magnetic sphere into which electrons are injected. The magnetic field squeezes the electrons into a dense ball at the reactor’s core, creating a highly negatively charged area. To begin the reaction, boron-11 nuclei and protons are injected into the cube. Because of their positive charge, they accelerate to the center of the electron ball. Most of them sail through the center of the core and on toward the opposite side of the reactor. But the negative charge of the electron ball pulls them back to the center. The process repeats, perhaps thousands of times, until the boron nucleus and a proton collide with enough force to fuse. That fusion turns boron-11 into highly energetic carbon-12, which promptly splits into a helium nucleus and a beryllium nucleus. The beryllium then splits into two more helium nuclei. The result is 'three helium nuclei, each having almost three million electron volts of energy,' according to Gay, who has written a paper explaining Bussard's research in layman's terms. The force of splitting flings the helium nuclei out from the center of the reactor toward an electrical grid, where their energy would force electrons to flow — electricity. This direct conversion process is extraordinarily efficient. About 95 percent of the fission energy is turned into electricity, Gay said."
"With funds running out, 'we banged it together as quickly as we could,' [Bussard said] and began testing in September. Instantly, Bussard saw 'impressive and startling results.' Later analysis would show that the rate of fusion was 100,000 times higher than in previous tests. 'We got four tests out of it that showed conclusively that we had solved the electron loss problem,' he said. That ended on Nov. 11, when the short circuit 'blew the machine apart,' Bussard said. But Bussard is convinced he had built a reactor that could produce more power than it would consume, and had found a way, at long last, to harness fusion as an energy source."
"Bussard may have proven that his process can use controlled fusion to produce more energy than it consumes, but he did not achieve sustained fusion or non-radioactive fusion, nor did he actually produce usable electricity. That will require more time and more money, he said.
"'From the beginning, we were always funded at one-eighth or one-tenth of what we really needed,' Bussard said. As a result, Bussard built tiny reactors. And because his reactors were small and his money was limited, Bussard had neither space nor funds to build cooling systems. Instead, to keep his equipment from overheating, he conducted his experiments using brief bursts of electricity to power the electromagnets at the heart of his reactors. Tests lasted 'fractions of milliseconds,' according to Gay. But actually, that's 'a long time from a nuclear perspective,' he said. Also because of power constraints, Bussard conducted his experiments by fusing deuterium rather than his preferred boron-11. Unlike boron, deuterium fusion produces neutron radiation. Bussard explained his choice: 'You need a lot of energy to cause fusion.' The requirement for 'boron fusion is very large — 200,000 volts. Deuterium takes a tenth that much.' Given the physical limitations of his small reactors and the fiscal limitations of his budget, 'It's much easier to work with deuterium,' Bussard said. Now that he has shown that controlled deuterium fusion is possible, it is simply a matter of building bigger reactors with bigger power supplies and cooling systems to demonstrate sustained boron fusion, he said. Bussard said his next step is to build a new reactor to replace the one destroyed in 2005. Ideally, he’d like to build two and use them to demonstrate to other scientists beyond doubt that his process works. For that, he says he needs about $2 million. To build a full-size reactor, Bussard said he needs about $200 million. 'We’ve solved the physics; now it's time for engineering development,' Bussard said. That means developing special reactor hardware, such as high-voltage power supplies, special transformers and switches that work in timeframes of sub-milliseconds. Some of that work may be challenging, 'but you don’t have to discover new things,' Bussard said."