Tiny bubbles create nuclear fusion -- maybe

[Gauracandra]

Tiny bubbles create nuclear fusion -- maybe

March 4, 2002 Posted: 6:22 PM EST (2322 GMT)

 

WASHINGTON (Reuters) -- Tiny bubbles imploding in a solution of acetone may have generated nuclear fusion, Russian and U.S. scientists said 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.