One Hundred Years of Fusion

Monday

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When I was a child I heard that practicable fusion power was thirty years in the future. That was more than thirty years ago, and it is not uncommon to hear that practicable fusion power is still thirty years in the future. Jokes have been made both about fusion and artificial intelligence that both will remain perpetually in the future, just out of reach of human technology — though the universe has been running on gravitational confinement fusion since the first stars lighted up at the beginning of the stelliferous era.

It is difficult to imagine anything more redolent of failed futurism than domed cities. Everyone, I think, will recall the domed city in the film Logan’s Run, which embodied so many paradigms of early 1970s futurism.

It would be easy to be nonchalantly cynical about nuclear fusion given past promises. After all, the first successful experiments with a tokamak reactor at the Kurchatov Institute in 1968 date to the time of many other failed futurisms that have since become stock figures of fun — the flying car, the jetpack, the domed city, and so on. One could dismiss nuclear fusion in the same spirit, but this would be a mistake. The long, hard road to nuclear fusion as an energy resource will have long-term consequences for our industrial-technological civilization.

Russian T1 Tokamak at the Kurchatov Institute in Moscow.

Like hypersonic flight, practicable fusion power has turned out to be a surprisingly difficult engineering challenge. Fusion research began in the 1920s with British physicist Francis William Aston, who discovered that four hydrogen atoms weigh more than one helium (He-4) atom, which means that fusing four hydrogen atoms together would result in the release of energy. The first practical fusion devices (including fusion explosives) were constructed in the 1950s, including several Z-pinch devices, stellarators, and tokamaks at the Kuchatov Institute.

Ever since these initial successes in achieving fusion, fusion scientists have been trying to achieve breakeven or better, i.e., producing more power from the reaction than was consumed in making the reaction. It’s been a long, hard slog. If we start seeing fusion breakeven in the next decade, this will be a hundred years after the first research suggested the possibility of fusion as an energy resource. In other words, fusion power generation has been a technology in development for about a hundred years. For anyone who supposes that our civilization is too short-sighted to take on large multi-generational projects, the effort to master nuclear fusion stands as a reminder of what is possible when the stakes are sufficiently high.

The Z machine at Sandia National Laboratory.

I characterized fusion as a “technology of nature” in Fusion and Consciousness, though the mechanism by which nature achieves fusion — gravitational confinement — is not practical for human technology. Mostly following news stories I previously wrote about fusion in Fusion Milestone Passed at US Lab, High Energy Electron Confinement in a Magnetic Cusp, One Giant Leap for Mankind, and Why we don’t need a fusion powered rocket.

There was a good article in Nature earlier this year, Plasma physics: The fusion upstarts, which focused on some of the smaller research teams vying to make fusion reactors into practical power sources. Here are some of the approaches now being pursued and have been reported in the popular press:

● High Beta Fusion Reactor The legendary Skunkworks, which built the U-2 and SR-71 spy planes, is working on a fusion reactor that it hopes will be sufficiently compact that it can be hauled on the back of a truck, and will produce 100 MW. (cf. Nuclear Fusion in Five Years?)

● magnetized liner inertial fusion (MagLIF) This is a “Z pinch” design that was among the first fusion device concepts, now being developed as the “Z Machine” at Sandia National Laboratory. (cf. America’s Underdog Fusion Experiment Is Closing In on the Nuclear Future)

● spheromak A University of Washington project formerly called a dynomak, a magnetic containment device in the form of a sphere instead of the tokamak’s torus. (cf. Why nuclear fusion will soon become reality)

● Polywell The Polywell concept was developed by Robert Bussard of Bussard ramjet fame, based on fusor devices, which have been in use for some time. (cf. Low-Cost Fusion Project Steps Out of the Shadows and Looks for Money)

● Stellerator The stellarator is another early fusion idea based on magnetic confinement that fell out of favor after the tokamaks showed early promise, but which are not the focus of active research again. (cf. From tokamaks to stellarators)

This is in no sense a complete list. There is a good summary of the major approaches on Wikipedia at Fusion Power. I give this short list simply to give a sense of the diversity of technological responses to the engineering challenge of controlled nuclear fusion for electrical power generation.

Polywell Fusion Reactor

Even as ITER remains the behemoth of fusion projects, projected to cost fifty billion USD in spending by thirty-five national governments, the project is so large and is coming together so slowly that other technologies may well leap-frog the large-scale ITER approach and achieve breakeven before ITER and by different methods. The promise of practical energy generation from nuclear fusion is now so tantalizingly close that, despite the amount of money going into ITER and NIF, a range of other approaches are being pursued with far less funding but perhaps equal promise. Ultimately there may turn out to be an unexpected benefit to the difficulty of attaining sustainable fusion reactions. The sheer difficulty of the problem has produced an astonishing range of approaches, all of which have something to teach us about plasma physics.

Stellarator devices look like works of abstract art.

Nuclear fusion as an energy source for industrial-technological civilization is a perfect example of what I call the STEM cycle: science drives technology, technology drives industrial engineering, and industrial engineering creates near resources that allow science to be pursued at a larger scope and scale. In some cases the STEM cycle functions as a loosely-coupled structure of our world. The resources of advanced mathematics are necessary to the expression of physics in mathematicized form, but there may be no direct coupling of physics and mathematics, and the mathematics used in physics may have been available for generations. Pure science may suggest a number of technologies, many of which lie fallow, with no particular interest in them. One technology may eventually come into mass manufacture, but it may not be seen to have any initial impact on scientific research. All of these episodes seem de-coupled, and can only be understood as a loosely-coupled cycle when seen in the big picture over the long term.

In the case of nuclear fusion, the STEM cycle is more tightly coupled: fusion science must be consciously developed with an eye to its application in various fusion technologies. The many specific technologies developed on the basis of fusion science are tested with an eye to which can be practically scaled up by industrial engineering to build a workable fusion power generation facility. This process is so tightly coupled in ITER and NIF that the primary research facilities hold out the promise of someday producing marketable power generation. The experience of operating a large scale fusion reactor will doubtless have many lessons for fusion scientists, who will in turn apply the knowledge gained from this experience to their scientific work. The first large scale fusion generation facilities will eventually become research reactors as they are replaced by more efficient fusion reactors specifically adapted to the needs of electrical power generation. With each generation of reactors the science, technology, and engineering will be improved.

The vitality of fusion science today, as revealed in the remarkable diversity of approaches to fusion, constitutes a STEM cycle with many possible inputs and many possible outputs. Even as the fusion STEM cycle is tightly coupled as science immediately feeds into particular technologies, which are developed with the intention of scaling up to commercial engineering, the variety of technologies involved have connections throughout the industrial-technological economy. Most obviously, if high-temperature superconductors become available, this will be a great boost for magnetic confinement fusion. A breakthrough in laser technology would be a boost for inertial confinement fusion. The prolixity of approaches to fusion today means that any number of scientific discoveries of technological advances could have unanticipated benefits for fusion. And fusion itself, once it passes breakeven, will have applications throughout the economy, not limited to the generation of electrical power. Controlled nuclear fusion is a technology that has not experienced an exponential growth curve — at least, not yet — but this at once tightly-coupled and highly diverse STEM cycle certainly looks like a technology on the cusp of an exponential growth curve. And here even a modest exponent would make an enormous difference.

This is big science with a big payoff. Everyone knows that, in a world run by electricity, the first to market with a practical fusion reactor that is cost-competitive with conventional sources (read: fossil fuels) stands to make a fortune not only with the initial introduction of their technology, but also for the foreseeable future. The wealthy governments of the world, by sinking the majority of their fusion investment into ITER, are virtually guaranteeing that the private sector will have a piece of the action when one of these alternative approaches to fusion proves to be at least as efficient, if not more efficient, than the tokamak design.

But fusion isn’t only about energy, profits, and power plants. Fusion is also about a vision of the future that avoids what futurist Joseph Voros has called an “energy disciplined society.” As expressed in panegyric form in a recent paper on fusion:

“The human spirit, its will to explore, to always seek new frontiers, the next Everest, deeper ocean floors, the inner secrets of the atom: these are iconised [sic] into human consciousness by the deeds of Christopher Columbus, Edmund Hillary, Jacques Cousteau, and Albert Einstein. In the background of the ever-expanding universe, this boundless spirit will be curbed by a requirement to limit growth. That was never meant to be. That should never be so. Man should have an unlimited destiny. To reach for the moon, as he already has; then to colonize it for its resources. Likewise to reach for the planets. Ultimately — the stars. Man’s spirit must and will remain indomitable.”

NUCLEAR FUSION ENERGY — MANKIND’S GIANT STEP FORWARD, Sing Lee and Sor Heoh Saw

The race for market-ready fusion energy is a race to see who will power the future, i.e., who will control the resource that makes our industrial-technological civilization viable in the long term. Profits will also be measured over the long term. Moreover, the energy market is such that multiple technologies for fusion may vie with each other for decades as each seeks to produce higher efficiencies at lower cost. This competition will drive further innovation in the tightly-coupled STEM cycle of fusion research.

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Note added Wednesday 15 October 2014: Within a couple of days of writing the above, I happened upon two more articles on fusion in the popular press — another announcement from Lockheed, Lockheed says makes breakthrough on fusion energy project, and Cheaper Than Coal? Fusion Concept Aims to Bridge Energy Gap.

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Fusion and Consciousness: Technologies of Nature

Saturday

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Fusion: nature got there first

Fusion came very early in the history of the universe, and consciousness came very late in the history of the universe — this pair of natural technologies come so early and so late, respectively, that one could say that they “bookend” cosmological history as the Alpha and Omega of cosmic evolution.

After an initial period of big bang nucleosynthesis in the first twenty minutes of the life of the cosmos, the universe did little in the way of producing more baryonic matter until gravity took over, and the baryonic matter condensed into early stars. Stars began to “light up” about 100 million years after the big bang, which in cosmological terms is not a terribly long time. This “lighting up” of the stars has been said to mark the advent of the stelliferous era.

In the almost 14 billion years of the universe’s history, stars have been shining for all but the first 100 million years — the vast majority of the age of the universe. What this means is that fusion has been around for the vast majority of the history of the universe. Nature innovated fusion technology early on, and fusion has continued to be central to the natural processes of the universe up to the present time and for the foreseeable future.

It has been said that human beings are a solar species. I wrote about this in my post Human Beings: A Solar Species. To say that human beings are a solar species is to say that we are a species dependent upon fusion. All life, and not only our species, is dependent upon the energy generated by fusion, so that fusion is responsible for all (or almost all) subsequent emergent complexity.

Fusion is a basic technology of the universe, a conditio sine qua non of cosmological order and its history. As such, fusion is a robust and durable technology proved over billions of years. Fusion as a natural source of energy is achieved through gravitational containment, and while human technology is not yet in a position to exploit the technology of gravitational containment, we have a very clear idea of its mechanism, as we have sophisticated physical theories to account for it. In other words, we have a good understanding of a technology that is one of the early building blocks of the universe.

Other technologies of nature

It is interesting, in this context, to consider other natural technologies and their place in cosmological natural history. We know, for example, from a 1972 discovery at Gabon, Africa, that fission, like fusion, is a natural technology. At Oklo in Gabon, about 1.7 billion years ago, just the right elements came together with a critical mass of fissionables to produce self-sustaining nuclear chain reactions.

Fissionables are relatively rare, and we know that these heavier elements are created by supernovae, so that natural fission reactors cannot come about until after (at very minimum) generation III stars have gone supernovae and flung their radioactive remnants into the universe. The date of the natural reactor at Gabon makes it quite old, but still not half as old as the earth itself, and nowhere nearly as old as fusion. It has been proposed that there was a “paleo-reactor” on Mars in the distant past, and it is interesting to speculate how widely spread, or how rare, fission technology is in the universe. We will not know until we explore in detail.

Another natural technology of note is life itself. Current biological thought suggests that life emerged on earth not long after the planet began to cool. The Earth is thought to be about 4.54 billion years old, and life may have arisen as much as 3.9 billion years ago. In other words, the Earth has hosted life for much longer than its initial sterility. The earth has, in turn, existed for almost a third as long as the entire universe, so that means that life (at very least on earth, if nowhere else) has been around for a quarter of the age of the known universe. That makes life a well-established and robust natural technology.

A recent paper, Life Before Earth by Alexei A. Sharov and Richard Gordon, suggests that if the complexity of life is extrapolated backward in time we must posit an origin of life at about 9.7 billion years ago, which is almost twice as old as the earth, which suggests in turn that earth was “seeded” with life as soon as its was cool enough to support life, rather than independently arising on Earth. While this thesis is, in my judgment, rather tenuous, its cannot be dismissed out of hand, and if it is correct, it shows life to be an even longer-lived and more durable technology than we now suspect it to be.

Just as we are curious if there have been other naturally occurring fission reactors in the universe, we are intensely interested in the possibility of life elsewhere in the universe: the robust and durable technology of life on earth suggests that this technology may well be replicated elsewhere, as pervasive in the universe, where conditions are right, as fusion technology is pervasive in the universe. The existence of life elsewhere is the cosmos is one of the great scientific questions of our time.

Consciousness: nature got there first, too

In contradistinction to fusion, the technology of consciousness arrives late in the history of the universe. While there were likely rudimentary forms of consciousness prior to the particular forms of mammalian consciousness familiar to us both in ourselves and in the other mammals with whom we often share our lives, and mammalian consciousness is a robust natural technology about 160 million years old (interestingly, not so much more distant from the present as the lighting up of stars was distant from big bang), the intelligent, self-reflective consciousness of human beings seems to be even younger than the bodies of anatomically modern human beings.

The late emergence of consciousness in the history of the universe is interesting in so far as it demonstrates that the universe, even at its present advanced age, is still capable of technological innovation.

In regard to consciousness, we are closing in on the mechanisms of the brain that enable the emergence of consciousness from a material substrate, but, unlike the case with fusion, we have no idea whatsoever what consciousness is and have no theory to account for it. Of course I am aware that many will disagree with me on this — even, if not especially, those scientifically-oriented readers who found themselves nodding over what I wrote above about fusion, and who have convinced themselves of the truth of some reductivist or eliminativist theory of consciousness.

Hugo de Garis, who appeared in the film about Ray Kurzweil, Transcendent Man, said in an interview (Interview with Hugo de Garis: Approaches to AI, Neuroscience, Engineering, Intelligence Theory, Cyborgs interviewed, filmed and edited by Adam A. Ford) that, “…we have ourselves as the existence proof that nature has found a way to [build] a conscious, intelligent creature.” (We could, in the same spirit, say that stars are the existence proof of fusion energy.) This is a perfect evocation of the weak anthropic principle as applied to consciousness and intelligence: we’re here, and we’re conscious, therefore consciousness is possible and the universe is consistent with the emergence of conscious life.

The possibility of conscious knowledge of consciousness

These natural technologies are not just randomly jumbled together, but are in fact closely related. The fusion technology of stars enabled energy production that was exploited by life, which latter grew in complexity until it made possible the even more subtle and complex technology of conscious intelligence. The earliest of these technologies, fusion, we understand well; the latest of these technologies, not surprisingly, still eludes us.

And in saying that a full understanding of consciousness still eludes us, what we are saying is that consciousness so far understands the natural technologies that made itself possible, but it does not yet understand itself in the same way. We may yet attain the full measure of reflexive self-awareness of consciousness when consciousness knows itself in the same way that it understands fusion technology. This will take time, since, as we have noted, consciousness is a youthful technology of nature.

Consciousness may, too, someday become as pervasive in the universe as fusion. Indeed, the fact that we know, that we can see, that fusion is operating everywhere in the known universe, is the first precondition of life, and if life too has been made pervasive by pervasive fusion energy sources, the technology of life may, in the fullness of time, give rise to the technology of conscious intelligence. But consciousness is a late-comer in cosmological order, and has not yet shown itself to be a technology of nature as robust and as durable as fusion. Only the test of time can demonstrate this.

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