Taking the basic apparatus used in 2002, two Purdue researchers refined the experiment and published new results that once again seem to prove that nuclear fusion was taking place. If it proves to be real, the new approach might lead to a genuine new source of energy.
An inexpensive, practical method of controlling nuclear fusion could revolutionize energy production, so any hint of a breakthrough in that direction generates high interest among both the technical community and the mainstream media. But hard-headed physicists have grown wary of "fusion in a jar" experiments.
The physics community was lukewarm to n approach to tabletop fusion that originated with Rusi Taleyarkhan at Oak Ridge National Laboratory in 2002. Using acoustic cavitation generated by ultrasound waves in a solution doped with deuterium, Taleyarkhan and his colleagues published results that they considered an airtight case for nuclear fusion. But criticism followed. When Taleyarkhan replied with a follow-up experiment to address those concerns, the reaction was muted.
The Purdue team began its work independently two years ago. "Sonofusion is thermonuclear fusion and is scalable," said Yiban Xu, who performed the experiment with fellow researcher Adam Butt. "However, much research and development needs to be done before reaching so-called energy break-even."
In the language of nuclear fusion researchers, break-even is the point beyond which a reaction produces more energy than it consumes, the minimal requirement for success. Xu, more concerned with proving that any nuclear fusion occurred, cannot say whether the reaction produces energy efficiently.
Xu said a small-scale apparatus like his experimental setup could have other important applications. "Neutrons seed cavitation in the test fluid, and so do the other nuclear particles. Therefore, in principle, cavitation occurrence indicates the presence of radiation activities if appropriate conditions are provided," he said.
Possible applications could be a simple and portable neutron source or a way to generate tritium, a helium isotope produced by the reaction.