Contained fusion explosions could potentially solve the world's epic challenges of energy, the economy and the environment. With the failure of the National Ignition Facility to ignite a "fusion pellet," the 50 year laser fusion program at Livermore Lab has clearly demonstrated the limitations of the laser as a "pellet driver" for energy production. Fortunately, a much more promising driver technology has been waiting in the wings: The particle accelerator.
The 21st century can and must be marked by the world's transition to nuclear fusion energy. It is, contrary to prevailing "wisdom," the only currently available solution. Specifically: a complete energy solution that uses existing (or doable) particle accelerator technology to ignite, contain and harvest the energy from clean and safe nuclear fusion explosions, and produces vast amounts of low cost energy and energy products.
I'm not asking anyone to believe any of this; not right away. The scientific evidence is there, as strong as ever (though a bit faded and dusty from 34 years of neglect) and it will come out eventually -- starting now, if I can help it. Though it may seem too radical or too big (given the size of our problems, how can any solution be too big?), the science clearly points to this technological approach as "the best bet" for near-term fusion energy.
Note: I believe that the scientific evidence also makes a strong case that this technology will produce highly economical energy, and will quickly establish itself --globally -- as the new baseload source of electricity and liquid fuels. If I didn't believe this, then I wouldn't bother with it in the first place; for I reject the notion that a combination of expensive energy technologies can somehow solve our problems -- no matter how "green" they appear on the surface. A true energy solution must be environmentally sustainable, but it must also create real wealth -- tangible, material, renewing, rejuvenating wealth -- on a scale that raises living standards throughout the world, allowing all of us to benefit from what modern technology and "civilization" have to offer.
Paraphrasing Churchill, I believe we Americans will finally do the right thing -- having tried everything else.
Contrary to popular belief -- and in sharp contrast to official statements from the U.S. Department of Energy -- we actually do possess the know-how to ignite, safely contain and control miniature fusion explosions, a process called inertial confinement fusion (ICF) (although this Wikipedia page is mostly about laser fusion, note the brief but intriguing reference to HIF at the end of section 1.3):
Heavy ion beams are particularly interesting for commercial generation, as they are easy to create, control, and focus. On the downside, it is very difficult to achieve the very high energy densities required to implode a target efficiently, and most ion-beam systems require the use of a hohlraum surrounding the target to smooth out the irradiation, reducing the overall efficiency of the coupling of the ion beam's energy to that of the imploding target further.
I have no idea who wrote this. The "downside" they describe is mostly outdated, except for the "very high energy densities" which has always been the basic challenge of the accelerator design: to produce very intense heavy-ion particle beams on the target. Indeed, the core of the project and the biggest technical challenge will be the design and construction of a very large particle accelerator system. By some measures, including overall cost, this system will be larger than the largest accelerator to date, which is the 27 km long
Large Hadron Collider (LHC) at CERN, on the French-Swiss border near Geneva. The overall length of the heavy-ion accelerator will likely be around half that, and it won't be in the shape of a big ring. It will, however, be underground in tunnels like the LHC, although it will have multiple parallel beam lines and so the tunnels will need to be much wider,
similar to this one.
No additional scientific breakthroughs are required; the path has already been cleared. We (some of those among us, that is) already know how to design and construct very large particle accelerator systems. This technology has been continually (if quietly and esoterically) developed for more than 80 years. It was first recognized in 1976 that a certain type of particle accelerator would make an efficient and practical "pellet driver" for igniting small fusion explosions. The accelerated particles in this case are "heavy ions" from the middle and lower parts of the periodic table. Xenon, tin, lead, bismuth, neodymium, samarium; these are a few examples. Accelerated to about half the speed of light over a distance of several miles, this beam of particles would be formed into a short, intense pulse before striking a fusion pellet, about 1 cm in diameter, at the center of a large vacuum chamber that contains (besides the tiny pellet) a large amount of liquid and solid lithium. The intense heat and pressure from the ions impacting and penetrating the pellet ignites a fusion reaction, in less than 1 microsecond, that explodes outwards, vaporizing and otherwise heating a large amount of lithium and releasing the energy equivalent of about 2 barrels of oil (BOE). This method of producing fusion energy is called heavy-ion fusion (HIF). Lithium is a critical ingredient as it absorbs the blast forces of the explosion, the heat of the explosion, and the inevitable fast neutrons from the deuterium-tritium reactions.
The main reason for HIF's holdup has been nuclear weapons -- the U.S. nuclear weapons program; the policies, institutions, money and secrecy surrounding it. The root of all this, of course, is the existential and terrifying threat posed by these weapons, and the top-secret knowledge -- the science and technology -- that makes them possible. Some of the knowledge that applies to thermonuclear fusion weapons also applies to miniature fusion explosions ignited by laser beams or particle beams.
Simply put, fusion weapons have trumped -- tripped up and delayed -- fusion energy.
In 2010 a remarkable article was published in Physics Today, by C. Martin Stickley. In 1976, Stickley was the official at ERDA (precursor to the Department of Energy) who convened the two-week scientific workshop at the Claremont Hotel in Berkeley in the summer of 1976. This letter (reproduced below in full) shines a light on a little-known episode in science history; an eyewitness account of the collision between science and politics that, it can be argued, delayed fusion energy development by 34 years.
I was the director of the Office of Laser Fusion at the Energy Research and Development Administration (ERDA) in 1976, as mentioned by Robert Burke in his letter (PHYSICS TODAY, June 2010, page 59). The participants in the first workshop on what became known as heavy-ion fusion (HIF) were an exceptional group from the fusion and accelerator communities. Their conclusions warranted high confidence. Accordingly, I stated in my remarks at the close of the meeting that the heavy-ion approach to inertial fusion faced “no showstoppers.” From that time on, I have believed that HIF is the approach to take for fusion energy.
Support for HIF for energy production in ERDA and its successor, the Department of Energy (DOE), was excellent in fiscal years 1977–79 as the monies needed to demonstrate the concept and to define a heavy-ion demonstration experiment (HIDE) were small—only $0.7 million in FY 1979. Costs were shared between the Office of Laser Fusion and the Office of High Energy and Nuclear Physics. John Deutch, then director of energy research, told me “to keep HIDE in the budget at any cost.”
The pressure to decrease HIF funding was great, for three reasons. First, laser fusion was viewed primarily as a military program, which made HIF, a non-weapons-lab program, a lower priority behind the mainline laser and light-ion programs. Second, the costs to achieve a scientific feasibility demonstration using the powerful lasers at Lawrence Livermore National Laboratory were large and rising. And third, Los Alamos and Sandia national laboratories, privately owned KMS Fusion (largely funded by the DOE laser fusion program), and the University of Rochester lobbied for ever greater funding for their inertial fusion programs. Members of the HIF community did not apply similar pressure.
I sought a $7.0 million budget add-on for HIF for FY 1979, but the House Appropriations Committee did not appropriate it, due to strong negative input from the House Armed Services Committee.
I was removed from my job as director in mid-FY 1979 for attempting to fund classified efforts in US industry, including Westinghouse’s attempt to develop automated pellet fabrication techniques. The Lawrence Livermore management interpreted my actions as a serious threat to the lab’s future. In parallel, budget pressures continued to increase, so money for constructing HIDE was scrubbed from the FY 1980 budget. As a result, the country has lost 30 years of progress that could have been made toward fusion energy. It is sad that magnetic fusion has gotten no further than it has, and yet we know that inertially confined fusion (ICF) is possible since we can create nuclear explosions.
In an interview with PHYSICS TODAY (September 2009, page 26), DOE undersecretary for science Steven Koonin expressed admiration for Glenn Seaborg’s approach during the Manhattan Project of “a shutting off of dead-ends . . . on the spot.” DOE would do well to restore that attitude. I wanted to cut the program that was developing a carbon dioxide laser, well known to be fundamentally hampered for driving pellet implosions by its long wavelength. Only years later was CO2 laser development dropped.
The upcoming National Academy of Sciences (NAS) review of ICF for power production will be a key step forward if HIF receives due consideration. That may be somewhat difficult, for three reasons. First, DOE may already have established its preference for driver selection; Undersecretary Koonin said, “I would keep an eye on NIF [the National Ignition Facility] as perhaps offering an alternative route to fusion energy.” Second, the experience I outline above shows the potential for interference from political and other nontechnical obstacles. And third, since virtually all inertial fusion funding for almost five decades has gone to laser and light-ion development, the NAS review will need to probe well below the surface to establish the advantages of HIF.
To be competitive, technologies, much like racehorses, need proper care and feeding. If the NAS review is to reach solid conclusions, serious options must be adequately funded beforehand in order to fully inform the NAS panel. Since leadership in the HIF technology has shifted to Europe and Russia, the NAS may need to tap the information available from those countries. The tremendous stakes involved should easily justify such an unusual step.
Finally, it is heartening that in the bill to reauthorize the America COMPETES Act, Congress has included language specifically calling on DOE to develop a plan to incorporate the NAS review’s recommendations.
C. Martin Stickley
PHYSICS TODAY, October 2010, page 8
Sadly but predictably, the main conclusion of the NAS review panel that Stickley refers to,
published earlier this year, merely confirmed the "party line" regarding ICF -- that the successful ignition of a pellet must first be demonstrated with the NIF laser before serious funding for an ICF energy program can be considered; a political rather than technical position that defers to the wishes of NIF and the nuclear weapons establishment. To illustrate this, consider the following excerpts from previously published reports reviewing ICF technology, some of which the NAS panel even referenced in its final report.
• The 1979 Foster Committee produced a classified report which is hidden some place in the bowels of the DOE. However, Johnny Foster reported to the Energy Research Advisory Board at its May 3, 1979, meeting saying, "heavy ion accelerators have great promise as reactor candidates because of their inherently high efficiency, developed repetitive-pulse technology, and favorable theoretical predictions of target coupling."
• The Jason Report of January 1983 (JSR82-302) stated, "We conclude that the uncertainties in coupling physics for high-energy heavy ions are minimal."
• The National Academies of Sciences Report of March 1986 entitled, "Review of the Department of Energy's Inertial Confinement Fusion Program" stated "Heavy ion beams may well be the best eventual driver for energy applications."
• The 1990 report of the Fusion Policy Advisory Committee (Stever Panel) recommended parallel development of inertial and magnetic fusion with a budget level of about $30 million per year for HIF.
• The 1993 Fusion Energy Advisory Committee (Davidson Panel) said, "We recognize the great opportunity for fusion development afforded the DOE by a modest heavy-ion driver program that leverages off the extensive target program being conducted by the Defense Department… ."
• The 1996 FESAC (Sheffield) report said, "In agreement with previous reviews, we consider the heavy ion accelerator to be the most promising driver for energy applications."
Not everyone with a relevant pay-grade has quietly acquiesced to the predominance of laser fusion over heavy-ion fusion -- of fusion weapons over fusion energy. Check out what Burton Richter, Nobel Laureate, had to say in 1994. An excerpt:
"What is not said is that nearly 16 years after the first Foster panel report, the heavy ion program is still starved for funds, and we have made very little progress on 'the best bet.' "
Some experts criticize heavy ion fusion (HIF -- the heavy-ion pellet driver approach) as being too expensive. Although the cost of an accelerator system for energy production would indeed be many billions ($20 billion by some estimates), judging the cost as "too expensive" or "economically viable" only makes sense in the context of how much energy the system can produce. It costs many billions, for example, to develop a giant oil or gas field, but this cost is justified by the expected amount of production revenue.
When imagining a fusion power plant, most experts limit themselves to the conventional model of a 1 GW or 2 GW electricity producer. But the model that makes sense for a HIF power plant turns out to have more in common with a giant oil field, both in the amount of energy produced and in the principal product: liquid fuels.
The economies of scale are such that the total output of low-cost energy products (hydrogen, synthetic liquid fuels, electricity, desalinized/purified water, etc.) should be at least 50 GW for the system to be highly profitable. This is based on the assumption of $20 billion to build the first heavy-ion accelerator system. This "high cost" is necessary to overdesign (design with margin) the first system in order to ensure -- guarantee -- that the pellets will ignite and produce large amounts of energy. Failure is not an option, and the first system must be an economic success. Knowledge gained from operating the first system will allow engineers to optimize and lower the cost of next-generation designs.
50 GW is a large number for a power plant (according to Wikipedia, China's Three Gorges Dam is 22.5 GW and Japan has a nuclear plant rated at 8.2 GW). This power will be divided among 10 or 20 pellet chambers, each producing 5 to 10 GW of fusion heat that will be used to make the energy products mentioned above. Pellet explosions can occur at a rate of about once every second, the time needed to clear the chamber and prepare for the next "shot." The accelerator system, however, is quite happy to drive pellets at 10 per second or more. Therefore, the accelerator system will drive the 10 or 20 pellet chambers (large underground systems themselves; separated from each other by hundreds of meters) similar to the way in which spark plugs sequentially ignite gasoline explosions in the cylinders of a car engine.
In the end, there's one big reason to be confident that this will work, or that we should at least give it a serious try. Accelerator physics and engineering is a very mature technology with a phenomenal 80 year record of success. Like modern aircraft design, a large accelerator can essentially be designed and operated "in the computer" such that its actual operation and performance can be predicted with a high degree of confidence. Therefore, we should leave it up to accelerator physicists and engineers to tell us, after running their calculations and computer simulations, what the accelerator design would look like, how "easy" or "difficult" it would be, and most importantly, how much it would cost.
But where do we start? It would be nice to see a Congressional Committee formed to acquire the testimony of experts and bring the true story, scientific and historical, of fusion energy out from under the shadow and secrecy of the nuclear weapons program where it's been sequestered these past 34 years. So I encourage you to call your Congressperson and demand a Congressional investigation of the U.S. Department of Energy for their negligent managing of fusion energy development in general, and heavy ion fusion in particular, but I wouldn't hold my breath; the House Armed Services Committee would probably block it, just as they blocked the continuation of DOE funding for the HIF program in 1979.
A privately funded investigation sounds more doable -- an open scientific conference and public forum on HIF and the various related scientific fields. Of course such a conference would itself cost millions. If you're interested and would like to make such an investment in our planet's future, please let me know. I know who to talk to for lining up experts to testify.