Posted on 02/18/2005 11:29:31 AM PST by Arkie2
Nuclear fusion is nature's atomic power It is three years since Professor Rusi Taleyarkhan made the controversial claim that he had achieved one of the holy grails of science - nuclear fusion. Since then, he has grown tired of the scepticism of his fellow scientists.
"My lab has been audited, my instruments have been audited, my books have been audited, the data speaks for itself.
"The data has to speak for itself - I mean how can I answer that I know absolutely 100% sure that it is what I think it is? I just have to look at the data and the data have been looked at very carefully.
"In the history of publication I probably will not be able to find one that has gone through this level of scrutiny - if you do, let me know," he said.
Sonoluminescence
Nuclear fusion is nature's atomic power - it is what powers the Sun and, if it can be made to happen here on Earth on a large enough scale, it promises to solve all of mankind's energy problems in one go.
It would be clean, last for ever and create no long-term nuclear waste. And Rusi Taleyarkhan claims to have achieved it using simple sound waves.
His breakthrough is based on something called sonoluminescence. It is a process that transforms sound waves into flashes of light, focusing the sound energy into a tiny flickering hot spot inside a bubble.
It has been nicknamed "the star in a jar" by researchers in the field.
The star in a jar effortlessly reaches temperatures of tens of thousands of degrees, which is hotter than the surface of the Sun. It was able to do all this by simply focusing the energy of the sound wave into a tiny hot spot.
The data speaks for itself
Professor Rusi Taleyarkhan In order to get fusion, temperatures inside the bubble had to be in the region of 10 million degrees. It seemed improbable that the tiny hot spots could be this hot. But if they were - or if a way could be found to make them so - then a new route to nuclear fusion would be opened up.
In 1999, the US government made some research funds available and across America a few laboratories started to explore ways to try to turn their star in a jar into fusion. And Rusi Taleyarkhan got there first.
But there was one major criticism of Rusi Taleyarkhan's work.
When fusion takes place, particles called neutrons are given off. These are considered by scientists to be the key signature of nuclear fusion - but measuring neutrons on a small, laboratory scale had proven notoriously difficult in the past because neutrons also occur naturally in the Earth's environment.
Professor Taleyarkhan was also using them in part of his experiment. Many scientists were unconvinced that Rusi Taleyarkhan's neutron detection was as accurate as it needed to be to prove such a big claim.
To try to get to the bottom of the issue, the experiment was re-run by Mike Saltmarsh and Dan Shapiro, colleagues of Taleyarkhan's at the Oak Ridge National Laboratory. But, when they repeated the experiment, they couldn't find any evidence of fusion.
"If there had been fusion going on at the sort of rate that Taleyarkhan's paper was claiming we should have seen an enormous increase in the neutron detection and we didn't," said Mike Saltmarsh.
Scientific stalemate
Most of the key figures in the field lined up on the side of Mike Saltmarsh but they could not dispute that Rusi Taleyarkhan had found what he said he had found. It seemed to be a scientific stalemate.
Taleyarkhan has had to battle the sceptics Then two years later, in March 2004, Rusi Taleyarkhan came out with a new paper, showing even more fusion and more neutrons. This paper was thoroughly reviewed and published in another respected journal.
But some sceptics still were not satisfied.
Nuclear fusion from sound waves would be a huge scientific breakthrough. But to be convinced of it, many scientists wanted to see better evidence; evidence that was absolutely incontrovertible.
They wanted to look very carefully at the timing of the neutrons to see just how closely they were related to the flashes of light.
If they occurred at the exact same time, they would finally be convinced that fusion was taking place. The question was - just how exact did the measurements need to be?
Unique experiment
The sceptics wanted to time it with incredible accuracy - that of a nanosecond, or a billionth of a second. This was one measurement that, though possible to do, still had not been carried out by Rusi Taleyarkhan and his team.
The BBC Horizon programme decided to try to sort out the issue once and for all. It commissioned an independent team led by Seth Putterman to conduct a unique experiment.
Working from the instructions set out in Rusi Taleyarkhan's paper, it assembled the same key scientific conditions necessary to create nuclear fusion from sonoluminescence.
But to see if it could find fusion, we measured the neutrons and the flashes of light simultaneously with nanosecond accuracy, something that had never been done before.
Recording data nanosecond by nanosecond, Seth Putterman did not find a single neutron close enough to a flash of light for it to be considered the result of nuclear fusion. So the conclusion was negative.
Horizon put this conclusion to Rusi Taleyarkhan who said that several differences in the equipment could have affected the results.
It is very possible that other laboratories around the world will reproduce Rusi Taleyarkhan's fusion results but until then, the claim will attract great scepticism from the wider scientific community.
Horizon was broadcast on BBC Two on Thursday, 17 February, 2005.
Purdue and RPI have both achieved this. RPI was second, but had better instruments.
It is not technically cold fusion. The collapsing bubble creates a high temperature and pressure spot, but it is small enough that it doesn't provide enough boom to destroy the can.
They used deuterinated acetone as the working fluid. That is standard acetone chemically, but with the standard single proton hydrogen replaced with deuterium, a proton and a neutron. As the bubbles form in the low pressure region of the sound wave the acetone evaporates, then in the high pressure region the bubbles collapse.
It acts a bit like the military shaped charges, with the edges of the bubble adding vectorally. The tiny center of the collapsed bubble is hit with neutrons while at high pressure and temperature, and you get helium (two protons and one neutron) out with a bit of energy.
Helium will not stay bonded to the rest of the acetone, so you have a tendency of the acetone to poison itself after operating for a bit.
Some folks are working on turning this into a powerplant. The previous cold fusion work (in Utah) was a rediscovery of the Alverez effect.
in other words, until others can get a claim and fame on the discovery - it won't be recognized.
It seems that the pioneers are always crucified
There is a claim of a process that goes beyond this, and their is a company seeking capital to exploit both. Some question whether they are nothing more than a scam however.
I have lost the details but boot hill may remember.
Researchers report bubble fusion results replicated ~ Cold fusion no longer confusion
Thanks for the link. The team mentioned in this article as having replicated the results is the same team led by Taleyharkin who claimed to have detected fusion in 2002. The BBC team sponsored an attempt to replicate the experiment and reported that there was absolutely no evidence of fusion.
So, the beat goes on. This appears to be cousin to the cold fusion debate. Until the results can be replicated in other labs there's not much here in my opinion but I wanted other's opinions.
Just a WAG, but it would be interesting to know if sonoluminescence varies with latitude.
Question -- I wonder if my minor quibble with the use of the word "clean" in this context is justified: If fusion reactions blast out high-energy neutrons, perhaps the MSM should be dissuaded from calling it "clean" energy? Laymen are going to get the idea that clean means "safe." In fact, I've seen some pretty wild futuristic claims about cold fusion, e.g., where everything from wrist watches, to blenders, to automobiles, to nuclear submarines would all have their own little cold fusion nuclear power plant onboard, and big centralized power plants run by big utility companies would be a thing of the past. But I think these claims neglect the spray of neutrons you'd get out such devices . . . Or am I wrong about that?
If the set up is this simple, you'd think the experiment would be reproduced (or fail at being reprodueded)immediately all over the world, and the controversy would not be dragged out for years.
I saw stuff like this in a corner of the accelerator lab at BYU in the early 90s. It's kind of neato, but there's a big jump from random collapse to controlled generation. Although, I wonder if something like a laser might be acheived here...
Rule #1: The essence of scientific experimentation is that the experiment be replicable by others.
• "The data speaks for itself."
Rule #2: Data never speaks for itself.
• "US government made some research funds available...to turn their star in a jar into fusion...Rusi Taleyarkhan got there first."
Rule #3: The glare of light reflecting from gold can sometimes blind even the keenest eye.
Bottom line here, EATB, is even if this sonoluminescence is eventually shown to produce fusion, it is producing it in such minute amounts that the resulting neutron flux is masked by the very tiny amounts of background (natural) neutron radiation.
--Boot Hill
No, your BS detector is working just fine.
--Boot Hill
I always wondered about that too. The nuetrons can irradiate objects, can't they?
Of course, I imagine they're easily contained in the (hypothetical) retaining walls of a powerplant.
If it produces energy in tiny amounts, that could still be significant, because it could presumably be done on a larger scale.
I say presumably because their could be engineering or containment problems. But usually those sorts of problems are soluble.
As for the pollution question, neutrons are not a problem except possibly up close when they are moving very fast. So it's doubtful that you would power a wristwatch this way. But you would produce clean, cheap electric power that could charge batteries, charge hydrogen cells, and power the national electrical grid.
Hydrogen cells are totally useless as a source of "alternative" energy unless you find a clean, non-fossil method of breaking down water into hydrogen and oxygen. Using electricity from coal, oil, or natural gas fired power plants to produce hydrogen is worthless.
Inefficient is inefficient, irrespective of the scale.
• "...neutrons are not a problem except possibly up close when they are moving very fast."
What happens to an atom that absorbs one of those very fast neutrons? It becomes a radio-isotope.
--Boot Hill
Read later ping.
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