[cdn-nucl-l] Tabletop Fusion in the news

["Adam McLean" <adam.mclean@utoronto.ca>]

Posted on Yahoo News, on March 4, 2002 and at:
http://story.news.yahoo.com/news?tmpl=story&u=/nm/20020304/ts_nm/science
_fusion_dc
And the article in Science Magazine is at:
http://www.sciencemag.org/feature/data/hottopics/bubble/1067589.pdf
>From what I have read, the temperature on the sun's surface is about
6,000 deg K and although the core of the sun is about 15 million deg K,
there is also 250 billion atms of pressure there (see:
http://www.seds.org/nineplanets/nineplanets/sol.html).  Those sound
waves must be something else... It's good they suggest skepticism before
the results are replicated, though.  Unfortunately, the internet links
mentioned in the Science articles to more information about the HYDRO
code used to validate the claim are not working - I'll check again
tomorrow.

Adam

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Tiny Bubbles Create Nuclear Fusion -- Maybe 
Mon Mar 4, 5:58 PM ET 
By Maggie Fox, Health and Science Correspondent 

WASHINGTON (Reuters) - Tiny bubbles imploding in a solution of acetone
may have generated nuclear fusion, Russian and U.S. scientists said on
Monday, in an experiment that, if confirmed, represents a giant advance
in nuclear physics. 

  
The experiment was run in a series of beakers that would take up only a
corner of any tabletop, using what amounts to souped-up nail polish
remover and sound waves. 

Because the collapsing bubbles produced temperatures as hot as those
found in the sun, the experiment does not mean that the long-sought goal
of cold fusion has been achieved, scientists warned. 

But if it can be replicated, it could mean an easy way to generate
nuclear energy has been found -- one that mimics what the sun does and
that would be many times safer than current nuclear fission methods used
by modern-day power plants and makers of atomic bombs. 

Nuclear fusion joins, or fuses, hydrogen atoms or other light atoms in a
reaction that creates a third, heavier atom and creates energy as a
byproduct. This is how the sun generates heat and light. 

Bombs and nuclear plants use another process, nuclear fission, which is
the splitting of an atom such as uranium to create a burst of energy. 

Fusion is much more desirable as it can use the hydrogen found in water
and it produces fewer radioactive waste products. 

Reporting on their experiment in the journal Science, Rusi Pusi
Taleyarkhan of the Russian Academy of Sciences and colleagues at Oak
Ridge National Laboratory in Tennessee and the Rensselaer Polytechnic
Institute in Troy, New York, said they had created a special form of the
ordinary solvent acetone by substituting a variant of hydrogen called
deuterium for the hydrogen atoms found in an acetone molecule. 

They chilled it to the freezing point of water and pulsed it with sound
waves. Tiny bubbles, no larger than the size of a period, appeared and
then imploded, sending out flashes of light and, they said, high-energy
neutrons. 

The process is called "acoustic cavitation," a phenomenon studied for
nearly a century. 

Temperatures inside these bubbles can be about as hot as the sun's
surface, and recent experiments suggest they can be even hotter -- 10
million degrees or as hot as the temperatures inside the sun where
nuclear fusion takes place. 

"If the results are confirmed this new, compact apparatus will be a
unique tool for studying nuclear fusion reactions in the laboratory,"
Fred Becchetti of the University of Michigan wrote in a commentary on
the findings. 

"But scientists will -- and should -- remain skeptical until the
experiments are reproduced by others. Many, including the author, could
not reproduce past claims made for table-top fusion devices," Becchetti
added, referring to a now-discredited 1990 experiment that made
headlines when scientists said they had caused nuclear fusion in what
amounted to a glass of water at room temperature. 

Becchetti added that Monday's report had been reviewed by other
scientists and was "credible until proven otherwise." 

An immediate challenge has already come from the Oak Ridge National
Laboratory, which helped conduct the experiment. The lab reviewed the
work and said its scientists could find no evidence of the key neutron
emissions. 

Taleyarkhan, who could not be reached immediately for comment, said the
reviewing scientists had improperly calibrated their detector and
misinterpreted the findings, Science said in a statement.