For a small but growing band of followers, October 28th, 2011 was a big day in the history of energy generation. The buzz centres around inventor/entrepreneur, Andrea Rossi, and his creation, the Energy Catalyzer or E-Cat for short. Rossi’s most fervent supporter, Hank Mills, even describes the above date as E-Day. Briefly, the E-Cat is a Cold Fusion device which really did seem to work on the above date to the satisfaction of a paying customer. Now, just before you click to another article entirely, take a deep breath. Yes, you are probably remembering the announcement of the Cold Fusion “breakthrough” by Martin Fleischmann and Stanley Pons in 1989 and how it and they quickly became discredited, mostly because other scientists could not reproduce their results and partly because they had tried to short-cut the peer-review publishing protocol which all “slow and serious” research should conform to.
More on this in a later article but let’s remember that “conventional” Nuclear Power is based on the energy released when massive nuclei such as Uranium or Plutonium are made to split – undergo controlled fission – resulting in large amounts of energy being released. As we also know, there are many drawbacks to this technology, mostly centering around short and long term radiation dangers. In wake of Chernobyl and now Fukushima, Fission Power obviously has a long and rocky public relations comeback trail to walk. One ray of hope for fission, though, is that the latest designs are a great deal safer than the Chernobyl and Fukushima ones. Another is greater use of Thorium, so we may yet see a nuclear renaissance when relatively clean fission power can play its part in slowing global warming.
But fission is not the only way to tap into the enormous energy locked up in the nucleus. The major alternative is Nuclear Fusion. Broadly, that is where lighter nuclei are made to collide with even lighter ones like protons or deuterons. In “hot” fusion, that collision must be made at very high energies – high enough to overcome the electrostatic repulsion of the two positively charged particles so that they they can get close enough to “fuse”. That is when the nuclear reactions can occur. Not all nuclear reactions are “exothermic” – net energy releasing – but, of those that are, many release much larger amounts of energy than ordinary exothermic chemical reactions like coal and oil burning do.
Nuclear fusion is, of course, the way all active stars, including our Sun, generate their energy. Nature beat Man to it 13 billion years ago. Even before the first hydrogen bomb test horrifically proved that man made nuclear fusion energy was possible, the quest for a safe and controlled form of it had been under way in earnest. It has been a very long project. Many of the original scientists have since died of old age(!) but their research descendants have doggedly continued. However, it is important to keep in mind, in view of the comparatively recent scorn poured on cold fusion that, even from the very early days of hot fusion, there have been premature claims of success, followed by red faces soon afterwards. The first was as early as 1951 and I myself, as a schoolboy in 1958, remember the fanfare when the ZETA appeared to be producing sustained, hot fusion. Researchers ultimately learned to be more guarded.
Hot fusion broke into two major camps – Magnetic Confinement and Laser. In the former, strong magnetic fields try to keep a hot plasma together for long enough for fusion to generate at least as much energy as it took to heat the plasma in the first place. In the latter, one high powered laser, or an array of them, fires an intense burst of energy onto a small deuterium/tritium rich pellet. That target must be constantly replaced. If I needed to “pick a winner” from just these two, I’d go for the laser approach but neither has yet succeeded in generating more energy than they use and each requires very expensive and exotic equipment. There are also nagging questions about the availability of tritium, a very rare isotope of hydrogen which must be created by atomic beams or in nuclear reactors and which is itself radioactive, albeit mildly in comparison to Plutonium.
However, still with hot fusion, much less expensive devices have been suggested and partly developed. My favourite of these is the Polywell. Its a long a complicated story but the bottom line is that it could be proved or disproved by the construction of a single, full scale model at a cost of 200 million US dollars. That may sound a lot but remember that its bigger brothers – Magnetic Confinement and Laser have so far run up a combined tab in the tens of billions. They don’t call it “Big Physics” for nothing – which brings us to one obvious reason as to why the hot fusion groups would hate to see cold fusion succeed: their own funding would disappear and they’d need to rapidly re-invent themselves – perhaps even as cold fusion “experts”!
That’s probably enough for modern attention spans. Your homework is obviously to study all the above links. Next time we’ll focus more on Cold Fusion, the E-Cat and whether we can dare to believe.