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Nature reveals serious doubts over claims for fusion in collapsing bubbles.
Nuclear engineer Rusi Taleyarkhan's claims that he had achieved table-top fusion in collapsing bubbles caused a storm when they were first reported in Science in 2002. If the effect is real, and could be harnessed, it might one day provide an almost limitless source of energy.
Posted by Nicola Jones on March 08, 2006
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Sorry I missed your article in October. The Department of Energy did not fund Dr. Taleyarken's work on sonoluminescence; the Defense Advanced Research Projects Agency did. DOE funded Dr. Saltmarsh and Dr. Shapira to take neutron measuremtents on Dr. Taleyarken's experiment at ORNL.
Posted by: Anne Davies | March 8, 2006 02:36 PM
The US Patent and Trademark Office file on Taleyarkhan's patent application states that the department of energy is the assignee of that application, and I quote: "The United States Government has rights to this invention pursuant to Contract No. DE-AC05-000R22725 with UT-Battelle, LLC, awarded by the United States Department of Energy."
Furthermore, Oak Ridge National Lab is run by UT Battelle on behalf of the US Department of Energy and Taleyarkhan was an employee at Oak Ridge at the time.
Posted by: Eugenie Samuel Reich | March 8, 2006 11:04 PM
I posted a comment earlier but you may wish to edit it with this one. The 2002 Science paper and 2004 Physical Review E paper by Taleyarkhan were funded by DOD, while the Physical Review Letters paper reporting negative results by Shapiro and Saltmarsh credits DOE. The filing of Taleyarkhan's now-abandoned patent application through the DOE reflects the fact that he was himself employed by Oak Ridge, a DOE lab with some oversight of his research, and a DOE tech transfer office on site.
Posted by: Eugenie Samuel Reich | March 9, 2006 03:13 AM
Cold Fusion is too important a possibility for physics profs to fuss with its science. Work in this area should be better funded,closely watched, and heavily pursued. I am a physicist & there's just enough hope to make this a real solution.
Posted by: Leonard Rich | March 9, 2006 05:49 AM
Critical analysis is crucial in critisism. Seems
to be that 'the Music of the Spheres' will be lost
for another 3,000 years.
Too bad for mankind..stick
with preconceptions and the 'fogotten' lessions will still be obscured.
Posted by: Edward John Mohr | March 10, 2006 03:07 PM
First, lets not confuse bubble fusion with cold fusion, it may be class of phenomenon also related to condensed matter physics. Sure it may not produce much energy, but if experimental results can be replicated by those with appropriate equipment, it may help demonstrate that large scale fusion is not the only game in town, for after more than 50 years of research it hasn't proven commercially viable either.
Posted by: V Golubic | March 12, 2006 01:33 AM
What this does remember to me the old Pons and Fleishman's case?
Posted by: A. Tiburcio-Silver | March 14, 2006 01:46 PM
Why do you think fusion energy will be "green"? It seems to me that any time you have neutrons flying around, they end up hitting a nucleus somewhere, and you transform your surrounding materials into radioactive waste.
Posted by: Richard Schwartz | May 11, 2006 01:28 AM
It is a common misunderstanding to think that if fusion can be mastered in any way, it will automatically provide an energy source. In fact, fusion reactions are quite simple to produce in table-top apparatus, as is demonstrated by the wonderful chrystal accelerator by Seth Putterman et.al.
The point, however, is that in all these devices a lot more energy is needed to create the fusion reactions than is released as fusion power. Since the discovery of the Lawson criterion, fusion scientists now that you need to keep together a hot fusion plasma at a sufficient density and temperature, for a sufficient length of time. For that, you need industrial-sized tokamaks such as the ITER-device. Anything smaller may be a wonderful way of making neutrons, but it will not be a net source of energy.
Mark Tiele Westra
Public Information Officer
European Fusion Development Agreement (EFDA)
Posted by: dr. M.T. Westra | May 16, 2006 06:30 AM
To me, Taleyarkhan's results look very convincing, while Naranjo's criticism does not. How does his virtual "Cf-252 source" distinguish between a deuterated sample and an un-deuterated one? And how between a setup with cavitation "on" and "off"? The fact that the response of the LS detector to the fusion neutrons does not look like an "ideal" 2.5 MeV spectrum, from my own experience, is most likely due to the simple presence of (elastically and inelastically) backscattered fusion neutrons from the surrounding walls and floors of the laboratory and other nearby material.
Posted by: Wolfram von Witsch | June 1, 2006 01:17 PM
Elaborating on my previous comment of June 1, 2006, I estimate that (depending on the exact geometry of the experimental setup) more than 70% of the fusion neutrons produced into the solid angle of the scintillator detector were lost due to scattering in the test liquid itself. However, most of these were replaced by in-scattered fusion neutrons, which were originally emitted in other directions and then, of course, are detected having lower energies. This by itself should pretty much explain the observed shape of the proton recoil spectrum.
Posted by: Wolfram von Witsch | June 7, 2006 03:56 PM
Unreproducability of experimental results has been a big setback for Cold Fusion, such as in this topic. An explanation of the general problem:
The usual explanation given by Hot Fusion mainstream physicists for why they don't take Cold Fusion more seriously is the problem of unreproducability of Cold Fusion experimental results.
I have never been happy about this explanation because many real phenomena are elusive. Elusive phenomena have often been at the cutting edge of much important research, not least in particle physics, my first specialty.
It occurred to me a few days ago that there may be an explanation of Cold Fusion's problem in the extreme, multiscale variability of meson densities in the meson soup at the bottom of Earth's atmosphere.
There is much evidence that mesons catalyse Cold Fusion reactions by greatly reducing Coulomb (electrical repulsion) barriers between Deuterium atoms via replacement of orbital electrons, starting with Luis Alvarez et al's 1957 work.
Such catalysis would be strongly dependent on particles densities of mesons of optimal energies. There may on some occasions be a significant background component of such particles generated by cosmic ray interactions with the Earth's atmosphere that has not been taken into account by researchers.
The energies of cosmic ray interactions with the Earth's atmosphere cover an enormous energy range. Energy interactions near the bottom of this range are extremely frequent. Energy interactions near the top of this range are extremely infrequent.
The optimal energy of interactions producing mesons most strongly affecting Cold Fusion reactions would be between these two extremes. The frequency of occurrence of these optimal energy interactions, and sub-optimal intervening periods, would be somewhere between the extreme frequencies of these extreme interactions.
This intermediate frequency may well be of the order of the frequencies of Cold Fusion experiments producing contradictory results . . . Hence unreproducability of Cold Fusion experimental results:
While successful Cold Fusion experiments have generally been done within optimal meson soups, unsuccessful Cold Fusion experiments have generally been done within sub-optimal meson soups.
Posted by: Peter Nielsen | August 22, 2006 02:02 AM
A better version of this morning's:
Unreproducability of experimental results has been one of Cold Fusion's biggest problems, such as in this topic. An explanation of the general problem:
The usual explanation given by Hot Fusion mainstream physicists for why they don't take Cold Fusion more seriously is the problem of unreproducability of Cold Fusion experimental results.
I have never been happy about this explanation because many real phenomena are elusive. Indeed, such phenomena have often been at the cutting edge of much important research, not least in particle physics, my first specialty.
It occurred to me a few days ago that there may be an explanation of Cold Fusion's problem in the extreme, multiscale variability of meson densities in the background meson soup of the bottom of Earth's atmosphere.
There is much evidence, starting with Luis Alvarez et al's 1957 work, that mesons catalyse Cold Fusion reactions by greatly reducing Coulomb (electrical repulsion) barriers between Deuterium atoms via replacement of orbital electrons.
Such catalysis would be strongly dependent on significant densities of meson particles of optimal energies, which may on some occasions be generated by cosmic ray interactions with the Earth's atmosphere, which may not have been taken into account by researchers.
The energies of cosmic ray interactions with the Earth's atmosphere cover an enormous energy range. Interactions near the bottom of this range are extremely frequent. Interactions near the top of this range are extremely infrequent.
The optimal energy of interactions producing mesons most strongly affecting Cold Fusion reactions would be between these two extremes. The frequency of occurrence of these optimal energy interactions, and sub-optimal intervening periods, would be somewhere between the extreme frequencies of these extremes.
This intermediate frequency may well be of a similar order to the frequencies of Cold Fusion experiments. Hence contradictory results. Hence unreproducability of Cold Fusion experimental results:
While successful Cold Fusion experiments may generally have been done within optimal background meson soups, unsuccessful Cold Fusion experiments may generally have been done within sub-optimal background meson soups.
Posted by: Peter Nielsen | August 22, 2006 06:11 AM
A model for cold fusion may involve the buildup of high deuterium pressures and temperatures in microdefects in the palladium cathode with the applied voltage.The mechanism is similar to bubble and hot fusion except the coulomb barrier may be reduced at the defect surface by its orientatrion of the deuterium and its destortion of the deuterium electric field. Manufacture and heat treatment may need to be controlled to prevent variation in the size and number of such defects resulting in unreproducibility. Another source of unreproducibility is variation of the voltage during electrolysis causing surges in the microdefect pressure which may increase the size of the defects and the rate of fusion or may result in a network of fissures in the palladium destroying its effectiveness in cold fusion. At constant voltage, such effects are prevented since uniform pressures are maintained from the surface throughout the pallidium cathode.
Posted by: bill colley | September 7, 2006 03:05 PM