- 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.
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