February 01, 2006
More Rigorous Sonofusion Test Yields Positive Results

Can an easy way to tap fusion energy be developed? A new study on a way to create fusion with waves has found neutrons were generated by this approach.

Troy, N.Y. — A team of researchers from Rensselaer Polytechnic Institute, Purdue University, and the Russian Academy of Sciences has used sound waves to induce nuclear fusion without the need for an external neutron source, according to a paper in the Jan. 27 issue of Physical Review Letters. The results address one of the most prominent questions raised after publication of the team’s earlier results in 2004, suggesting that “sonofusion” may be a viable approach to producing neutrons for a variety of applications.

By bombarding a special mixture of acetone and benzene with oscillating sound waves, the researchers caused bubbles in the mixture to expand and then violently collapse. This technique, which has been dubbed “sonofusion,” produces a shock wave that has the potential to fuse nuclei together, according to the team.

But other scientists were skeptical of the results from that earlier round of sonofusion experiments.

In response to earlier criticisms this group of scientists has tried a sonofusion approach that did not use a external source of neutrons.

The telltale sign that fusion has occurred is the production of neutrons. Earlier experiments were criticized because the researchers used an external neutron source to produce the bubbles, and some have suggested that the neutrons detected as evidence of fusion might have been left over from this external source.

“To address the concern about the use of an external neutron source, we found a different way to run the experiment,” says Richard T. Lahey Jr., the Edward E. Hood Professor of Engineering at Rensselaer and coauthor of the paper. “The main difference here is that we are not using an external neutron source to kick the whole thing off.”

In the new setup, the researchers dissolved natural uranium in the solution, which produces bubbles through radioactive decay. “This completely obviates the need to use an external neutron source, resolving any lingering confusion associated with the possible influence of external neutrons,” says Robert Block, professor emeritus of nuclear engineering at Rensselaer and also an author of the paper.

The experiment was specifically designed to address a fundamental research question, not to make a device that would be capable of producing energy, Block says. At this stage the new device uses much more energy than it releases, but it could prove to be an inexpensive and portable source of neutrons for sensing and imaging applications.

To verify the presence of fusion, the researchers used three independent neutron detectors and one gamma ray detector. All four detectors produced the same results: a statistically significant increase in the amount of nuclear emissions due to sonofusion when compared to background levels.

A way to produce energy from fusion would put a pretty permanent end to our energy woes. But using more conventional approaches to creating the conditions under which fusion happens looks like it will take decades before fusion reactors are a reality. Can a less conventional approach provide a cost effective solution much sooner? If it did the implications would be staggering. Energy is the only resource whose limits matter for what humanity can accomplish. There is no single mineral whose short supply would stop or reverse economic growth. With enough energy we can mold many types of matter into states that would allow those types of matter to substitute for whatever is in short supply.

Share |      Randall Parker, 2006 February 01 08:55 PM  Energy Tech

John said at February 2, 2006 3:43 AM:

I would like to add intelligence and time to the short list of things that limits humanity in what it can accomplish.

ACID said at February 2, 2006 5:23 AM:

And good intentions.

Steve said at February 2, 2006 5:37 AM:

When will these technologies get serious consideration? Ever since Pons and Fleischman's experiments in the 80's, this has not really gone away. Either there is something to it, or there isn't. Let's please find out.

Jake said at February 2, 2006 6:30 AM:

Too bad the climate change industry is a political movement not a scientific one.

If it was a scientific movement, the Kyoto treaty would have pooled the money from all signing nations. Those hundreds of billions of dollars would be used in a Manhattan type project to create power from fusion.

But that would mean a solution to the problem and that is the last thing the climate change industry wants.

Randall Parker said at February 2, 2006 3:54 PM:


This is what I find so disappointing about environmentalists. They do not press for research into solutions. Ten or twenty billion dollars per year in energy research would do wonders. The results would be lower costs and less pollution.

James Bowery said at February 2, 2006 5:40 PM:

When cold fusion first hit the news, Paul Ehrlic said that a cheap, nonpolluting form of energy in the hands of humanity would be like giving a fully loaded automatic weapon to a 5 year old.

Kurt said at February 2, 2006 7:52 PM:

I remember Paul Erlich's comment in 1989. It is precisely the reason why I no longer consider what environmentalists have to say of having any relevance whatsoever. Paul Erlich's comments makes it plain as day that the "green" are really watermellons (green on the outside, red on the inside). Every green I have ever met has been a leftist, either a socialist or outright commie. The greens are nothing but human trash as far as I'm concerned.

James Bowery said at February 2, 2006 7:59 PM:

It should be noted that the neutron flux reported from sonofusion is many orders of magnitude smaller than another desktop fusion device that has been used for decades: The Farnsworth Fusor.

Invisible Scientist said at February 2, 2006 10:11 PM:

Note that Japan and a few other advanced countries are not constrained by the oil lobby that uses every dirty trick in the book to slow down nuclear reactor research. This is one reason it is possible that within a decade the liquid metal IFR reactors will gain momentum. Oil companies will do everything possible to reduce the funding for fusion and nuclear enerby research, but if there is a worldwide energy crisis, then things will change. One reason Iran might change its mind and stop developing nukes (at least on the surface) is because if there is an oil crisis, then even the oil lobby won't be able to stop the Bronx Project for energy. Last year, OPEC meetings concentrated on the danger (for them) that high oil prices might accelerate the development of the alternative energy sources.

Patrick said at February 3, 2006 2:15 AM:

OK. Lets say that tomorrow there is a fusion reactor that can produce practically free energy. Can this be turned into an automotive power source that is cost competitive with oil even at today's prices? No.

Even now, the cost of turning electricity into transport has the actual price of the coal powered electricity representing a tiny % of the actual cost per kilometre.

It would kill the greenhouse effect in its tracks (the greenies will think of something else) but oil would still be a big problem.

Unless of course the reactor is small enough to make a nuclear car possible.

Philip Sargent said at February 3, 2006 4:24 AM:

How far does a 14 MeV neutron travel in acetone I wonder? Presumably if the sonofusion events can be created in the body of the deuterated liquid, then there might be no irradiation of the structure. However, we presumably would get some additional isotopes of oxygen and carbon; and possibly a bit of tritium.

If it is mostly stable isotopes, then this could (eventually) possibly be a domestic or district heating system; not an electricity generator at all. Very useful.

Matthew Cromer said at February 3, 2006 11:16 AM:

Like meteorites, ball lightning and other phenomena that refused to go away just because most scientists used to scoff at the possibility of their existence, cold fusion research has led to an impressive amount of experimental evidence for its existence:


Perhaps someday in the not-too-distant future we will be driving electric cars with heavy water fuel tanks.

momochan said at February 3, 2006 1:53 PM:

Jake, wouldn't it be more precise to say that you support "technological" solutions to pollution, rather than "regulatory"?
Personally I support both solution styles. Regulation has its place in addressing the classic prisoner's dilemma that companies face in reducing pollution. Certainly there is a lot we can do in terms of the technology, particularly in terms of batteries and storage as RP has mentioned.
BTW, Feb 3 NYT says that the National Renewable Energy Lab in Colorado is having to let people go -- this is in spite of Bush's recent SotU address.

Randall Parker said at February 3, 2006 4:17 PM:


Very cheap energy could be turned into power for transportation. I can think of a number of ways to use cheap electricity to make liquid fuel to reduce the need for conventional oil:

1) Use electricity to split water to fix hydrogen to nitrogen to make fertilizer to grow crops that can be turned into ethanol.

2) Use electricity to turn coal into liquid, to heat up oil shale in the ground, and to heat up oil tar in Alberta.

3) Use electricity to split water and use the hydrogen to fix it to carbon soot left over from burning coal or from carbon from oil tires or any other carbon source including atmospheric carbon.

4) Power trains with electricity.

5) Use the cheap electricity to make large amounts of aluminum cheaply to make cars lighter to reduce the demand for liquid fuel.

6) Cheap electricity from fusion would be cheaper than natural gas for heating and electric generation. So all natural gas could be either liquified or used in compressed tanks in cars.

7) Use electricity to run indoor farms for biomass 12 months of the year.

Cheap fusion electricity absolutely would revolutionize our economy.

aa2 said at February 3, 2006 4:39 PM:

The key point someone mentioned above is that development of alternatives can happen in many different nations. Always most nations will want to stop the development because of their own vested interests.. but there is always at least one major nation that doesn't have that interest. For example Japan in the case of oil, with its heavy reliance on foreign oil, and lack of domestic oil companies.

I don't believe solutions to energy will have any chance of coming in America. As we already saw in the mid-70's what happened when something seriously threatened big oil and or king coal.

aa2 said at February 3, 2006 4:48 PM:

I've never met a green who wasn't also a communist either.

aa2 said at February 3, 2006 4:58 PM:

"Energy is the only resource whose limits matter for what humanity can accomplish."

Yep. And I don't think there is any physical limits to energy, at least for another couple order of magnitude jumps in global production. Food-->wood--->coal--->oil--->nuclear--future-->breeders.

And concious choices by civlizations to not develop energy I dont' think make any difference. Those civilizations will simply be overwhelmed by others that do develop.

Randall Parker said at February 3, 2006 5:39 PM:

My own enthusiasm for biomass as an energy solution is that it would require a lot of land and not a small amount of impact on the environment.

For example, I've calculated how much acreage of land it would take for corn to replace natural gas in the United States:

Corn farmers can grow 160 bushels per acre and get 392,000 btus per bushel. So corn produces 62.7 million btus per acre. What do other crops produce in btus per acre? I'm guessing most are much lower.

The United States uses about 23,000,000 million cubic feet of natural gas per year. Well, 1 cubic foot of natural gas has 1031 Btu of energy.

The acre of corn's 62.7 million btus divided by 1031 btu per 1 cu foot natural gas yields the equivalent of 60834 cubic feet of natural gas.

So how many acres of corn would be needed to produce as much energy as we get from natural gas per year? 23,000,000 million divided by 60,834. That's 378 million acres. At 160 bushels per acre that's 60.4 billion bushels. If memory serves US corn farmers currently grow between 11 and 12 billion bushels per year. So 5 times more corn would have to be put under cultivation for corn to replace natural gas.

E-P points to some grasses that can produce more heat energy per acre, perhaps as much as 3 times the heat produced per acre. But the 4 times more corn acreage is a very low estimate in the first place. The most productive land is in production now. To put more land into production we've have to put much less productive land into production. Either that or put lots of farm fields where rain forests now stand in places like Brazil.

I think some who fancy themselves as environmentalists for supporting corn ethanol and biodiesel haven't thought it all the way thru to just what scale of farming would be required for biomass to replace fossil fuels. I like the wilds. I like nature with birds, wild cats, bears, and the rest of it. I do not want to see much of that turned into farms. Do you?

Solar with very high conversion efficiency could provide just as much energy just on top of existing structures.

aa2 said at February 3, 2006 7:33 PM:

"I like nature with birds, wild cats, bears, and the rest of it. I do not want to see much of that turned into farms. Do you?"

Bingo... most 'greens' do not agree with you. They want small farming communes spread over the land... or the ones that do want 95% of the earth's population to disappear, so their communes won't spread over the whole world.

In America the footprint of man is now in retreat. More land is now returned to the wild each year then taken. The fallacy of the greens is to think that pastures, low efficiency crop raising and so on is 'natural'. Sure an oil well and pipeline looks more unnatural.. but if our transportation infrastructure in 2000 takes up less land then the farmland required for horses used in transportation in 1900 then we are really coming out ahead.

Philip Sargent said at February 4, 2006 3:59 AM:

The calculation on replacing methane with biomass gives an order of magnitude idea of the issue; but more appropriate would be to do the calculation for transport fuels (diesel, kerosene, petroleums of various kinds), rather than methane.

The most difficult transport fuel to replace (with something carbon neutral) is aviation fuel. This really has to be a kerosene-like fuel as ethanol has a poor energy density (which really matters in a plane). So, arguably, all biomass projects should be aimed at producing biokerosene/biodiesel, and the bioethanol proposals are a short-term fix which will have to be junked in 20 years anyway. By then, the ethanol industry would be an established vested interest, and they would fight it.

20 years is too short a time to bring in liquid H2 planes in significant numbers; given the mean lifetime of planes and the lead time on designing them.

Brett Bellmore said at February 4, 2006 9:13 AM:

I recall seeing a NASA study that suggested that you could run commercial aviation on beamed power. Sure, you lose a bit of the energy in transmission, but you gain an awful lot by not having to fly the fuel around.

Randall Parker said at February 4, 2006 12:37 PM:


My point on biomass energy is pretty simple: Going that way means massive increases in areas under cultivation. See my area calculations below.

We probably use a lot more energy from oil than we do from natural gas. So switching from oil to biomass would be even more massive a change.

Here's my rough estimate on the relative amounts of energy the US gets from oil versus natural gas. 1 barrel (42 gallons) of crude oil has 5.8 million BTU of energy and that same source puts a cubic foot of natural gas at 1026 BTUs (versus 1031 I used above and I'm guessing assumed temperature accounts for most of the difference.

The United States consumes almost 21 million barrels per day and the world 84 million barrels. 21 times 365 is 7665 million barrels. Okay, so lets convert our natural gas consumption into the more familiar crude oil equivalent of barrels per day. 5.8 million BTUs per barrel divided by 1026 BTUs per cubic foot works out to 5653 cubic feet of natural gas to get as much energy as a barrel of oil.

The US uses 23,000,000 million cu ft of natural gas per year divided by 5653 is about 4068 million barrels of oil equivalent energy. So the US uses almost twice as much energy from oil as from natural gas.

Take my 5 times more corn just to replace natural gas and it is more like a 15 times increase in corn production to replace natural gas and oil (and I might have made a mistake in these calculations and welcome corrections). Keep in mind that the marginal land that would be brought into production to do this might require 20 or 30 or 40 times the land area of current corn farms due to lower yield per acre. Cost per bushel would be much higher as well.

Since the US uses a quarter of the world's oil consumption then to replace all the world's oil consumption with corn energy (and ignoring energy loss in corn conversion to ethanol) we'd have to increase US corn production 40 fold. The price of corn and other foods would of course rise greatly as tomato, wheat, soy and other farms switched to corn. The biomass advocates need to think this this more.

Currently structures in the US cover an area equal to the state of Ohio. Ohio is 45,000 square miles. How does that compare to the area needed to grow corn? The 45,000 square miles for Ohio is 28,000,000 acres. Above I calculated that we'd need 378 million acres to grow enough corn to replace natural gas in the United States. Well, that's 13.5 times the area of Ohio. This ignores the need for roads and equipment areas. It also ignores lower yield in marginal land. Oh, and where to get all the water and what about chemical pesticide run-off?

To replace both oil and natural gas used in the United States with corn energy we'd need an area about 30 times the size of Ohio. Again, that underestimates the need due to access roads, living areas for the farmers, storage areas for equipment, and so on. Plus, again, crop yields will be much lower in marginal areas.

The CIA World Factbook puts total US land area at 9.6 million sq km. That is 3.7 million square miles. Well, 30 times the size of Ohio is 1.35 million square miles. That's about 36% of US territory. But most of that territory can't be used to grow corn. Alaska's no use. Ditto deserts and mountains.

So I do not see how this biomass strategy for energy works.

Again, I welcome corrections on any mistakes I made in these calculations.

Aside: While googling for the information above I came across a state by state map of pennies per gallon gasoline tax in the United States. Alaska (flush with oil royalties) charges only 8 cents per gallon and Wyoming only 14 cents per gallon. At the other extreme New York State charges 44.5 and California 41.6 cents per gallon.

Kurt said at February 4, 2006 1:01 PM:

The problem with the Tokamak is that it is a typical big-government program with all of the problems associated with bureaucracy. There are both technical and organization reasons why the ITER and tokamak, in general, will not work. Recently, the Chinese announced that they are going to build their own tokamak. Whether this indicates that they have a novel approach that could work or if they are just copying the West is not clear to me.

In addition to sonofusion, there are other fusion techniques. One I encountered at Los Alamos is the spheromak. There are 5 or 6 others. None of them are getting the funding that they ought to get, because it is all going to the tokamak, which cannot possibly work. The physicists backing the tokamak have lots of political clout and they have staked their careers on the tokamak. They are not about to allow an alternative method be tried, even if it has the possibility of being successful.

It looks like sonofusion is real. Whether it can be scaled to make commercial power remains to be seen.

If fusion is developed, it will be developed by private parties in the West, or by either private or government-funded parties in East Asia. It is unlikely that it will be developed in any other context.

Invisible Scientist said at February 4, 2006 6:44 PM:

One possibility is to ask the OIL COMPANIES to fund the fusion research. They are making so many hundreds of billions of dollars in this decade, that they might just get interested in a few years, because of the obvious calculation that
1) Oil will run out in 20 years
2) Fusion can become profitable only in 15-20 years.

Kurt said at February 5, 2006 12:51 PM:

The oil companies are large corporate bureaucracies. Although corporate bureaucracy is more efficient than government bureaucracy, they are still bureaucracies with all of the attendent problems. The corporate culture in the oil industry simply cannot change itself to accomodate and pursue R&D programs into stuff like fusion.

The Japanese have funded much fusion research, but their programs have all of the same problems as ours. Recently, however, they have started funding some of the alternative schemes (spheromak, reverse-pinch, Z-machine).

There is another problem as well. D-T fusion creates a neutron flux that is damaging to the chamber walls of the reactor. He3-T fusion does not have this problem. He3, however can be found only in space (Moon, outer planets, etc.). This is where sonofusion comes in, even if it cannot be scaled to make useful amounts of energy. Sonofusion has been shown to make both He3 and He4. Use the sonofusion to make the He3 that would then be used in a "conventional" fusion reactor. This eliminates the expensive effort to mine the moon and stuff like that.

Of course, the best fuel cycle for fusion is B-H. However, B-H fusion requires confinement conditions about 10 times greater than D-T fusion (100KeV for B-H fusion, 20KeV for He3-T fusion, and 10KeV for D-T fusion). There is no way the tokamak is ever going to do this. An alternative approach must be developed.

An X-prize for the development of commercial fusion power would be useful. There was some discussion of this in the early 90's, but it did not go anywhere. Its high time for such a prize system today.

Kurt said at February 5, 2006 1:06 PM:

One other pet peve about fusion stories in the media:

They always talk about the confinement conditions in temperature (like the plamsa is 100 million degrees in D-T fusion) and then make a big deal about such a high "temperature".

Energies of particles and plasmas are not measured in temperature degrees, they are measured in electron volts (eV or KeV). The e-beam in a CRT or standard television is around 11 KeV or 11,000 eV. Since one eV is roughly around 10,000 "degrees C", the e beam in your TV has an energy of around 100 million "degrees". Speaking of "100 million degree" sources, you've already got one in your living room (assuming you have a TV).

This, of course, is the idea behind the farnsworth fusor. You take the same set up that is used for a television, make it into a spherical arrangement, then you have a spherical accelerator system capable of producing fusion. Of course, the amount of energy yielded by the fusion reactions are a tiny percentage of the energy required to run the device. Hense, the farnsworth fusor is not capable of breakeven. Nonetheless, it is a useful tool to understand the principles involved in plamsas and particle beams necessary to understand what fusion is about. The farnsworth fusor can be built at home and some hobbyist have built them.

The farnsworth fusor was invented by Farnsworth, who also invented the television.

Brett Bellmore said at February 5, 2006 3:16 PM:

We already know how to achieve well above breakeven, in practice. The only problem is that the fuel "pellets" are a tad too large for conventional reactors.

However, I recall seeing a proposal some years ago to build a fusion reactor based on detonating small nuclear bombs in an extremely large underground cavity full of steam. The steam would absorb the blast before it could reach the chamber walls; All you had to do was tap the chamber for steam to drive a powerplant, inject replacement water, and periodicly drop a new bomb in when the temperature dropped too far.

Such a reactor would be perfectly feasible to build today, from a [i]technical[/i] standpoint. Politically it would be a nightmare.

Invisible Scientist said at February 6, 2006 12:44 AM:


Here is a discussion of the Boron - Hydrogen fusion concept by means of the colliding beams you were talking about:


and especially at:


But the Devil is in the details. We shall see if this can work...

Geothermal energy is also connected with your undergound nuclear explosion type power generators, because it is believed that the center of the planet is actually full of uranium that is slowly reacting to heat the iron that is surrounding it... If we had a way of drilling in a very efficient way, we could tap that kind of energy...

Tom said at February 7, 2006 6:25 PM:

I got to say, my alma mater has gotten quite good at getting out the PR. Go Engineers!

Paul Dietz said at February 8, 2006 12:51 PM:

I've never understood the excitement this sort of thing produces. Producing neutrons from fusion is easy. Producing hot plasma is easy. You can do both on a tabletop with amateur science level equipment. Producing a plasma that is hot and dense and confined long enough to produce positive energy payback is much much harder.

There is zero evidence that sonofusion, assuming it exists, will enable anyone to come anywhere close to breakeven, and good reason to think it will not. Ditto for IEC fusion (Farnsworth fusor).

Paul Dietz said at February 8, 2006 6:10 PM:

because it is believed that the center of the planet is actually full of uranium that is slowly reacting to heat the iron that is surrounding it.

Actually, uranium, thorium, and potassium are strongly concentrated in the continental crust, by several orders of magnitude over the average concentration in the planet. Much geothermal heat is produced in the crust itself, not farther down. This is reflected in the fact that the geothermal gradient (temperature increase per unit increase in depth) is much higher in continental crust than it is in the planet as a whole.

Mike Reisch said at April 24, 2006 9:15 PM:

At $72/barrel the in situ Fischer Tropsch process developed in Australia for turning coal into diesel oil is looking better every day.

Randall Parker said at April 24, 2006 10:04 PM:


What's your source for the $72 per barrel estimate for the Australian F-T process? I'm eagerly seeking information on coal-to-liquid costs. Whatever they are they put an upper limit on the price of oil.

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