Researchers Report Bubble Fusion Results Replicated

["Strom, Daniel J" <strom@PNL.GOV>]

http://www.rpi.edu/web/News/press_releases/2004/lahey.htm 



Physical Review E publishes paper on fusion experiment conducted with

upgraded measurement system



TROY, N.Y. - Physical Review E has announced the publication of an

article by a team of researchers from Rensselaer Polytechnic Institute

(RPI), Purdue University, Oak Ridge National Laboratory (ORNL), and the

Russian Academy of Science (RAS) stating that they have replicated and

extended previous experimental results that indicated the occurrence of

nuclear fusion using a novel approach for plasma confinement.



This approach, called bubble fusion, and the new experimental results

are being published in an extensively peer-reviewed article titled

"Additional Evidence of Nuclear Emissions During Acoustic Cavitation,"

which is scheduled to be posted on Physical Review E's Web site and

published in its journal this month.



The research team used a standing ultrasonic wave to help form and then

implode the cavitation bubbles of deuterated acetone vapor. The

oscillating sound waves caused the bubbles to expand and then violently

collapse, creating strong compression shock waves around and inside the

bubbles. Moving at about the speed of sound, the internal shock waves

impacted at the center of the bubbles causing very high compression and

accompanying temperatures of about 100 million Kelvin.



These new data were taken with an upgraded instrumentation system that

allowed data acquisition over a much longer time than was possible in

the team's previous bubble fusion experiments. According to the new

data, the observed neutron emission was several orders of magnitude

greater than background and had extremely high statistical accuracy.

Tritium, which also is produced during the fusion reactions, was

measured and the amount produced was found to be consistent with the

observed neutron production rate.



Earlier test data, which were reported in Science (Vol. 295, March

2002), indicated that nuclear fusion had occurred, but these data were

questioned because they were taken with less precise instrumentation.



"These extensive new experiments have replicated and extended our

earlier results and hopefully answer all of the previous questions

surrounding our discovery," said Richard T. Lahey Jr., the Edward E.

Hood Professor of Engineering at Rensselaer and the director of the

analytical part of the joint research project.



Other fusion techniques, such as those that use strong magnetic fields

or lasers to contain the plasma, cannot easily achieve the necessary

compression, Lahey said. In the approach to be published in Physical

Review E, spherical compression of the plasma was achieved due to the

inertia of the liquid surrounding the imploding bubbles.



Professor Lahey also explained that, unlike fission reactors, fusion

does not produce a significant amount of radioactive waste products or

decay heat. Tritium gas, a radioactive by-product of deuterium-deuterium

bubble fusion, is actually a part of the fuel, which can be consumed in

deuterium-tritium fusion reactions.



Researchers Rusi Taleyarkhan, Colin West, and Jae-Seon Cho conducted the

bubble fusion experiments at ORNL. At Rensselaer and in Russia,

Professors Lahey and Robert I. Nigmatulin performed the theoretical

analysis of the bubble dynamics and predicted the shock-induced

pressures, temperatures, and densities in the imploding vapor bubbles.

Robert Block, professor emeritus of nuclear engineering at Rensselaer,

helped to design, set up, and calibrate a state-of-the-art neutron and

gamma ray detection system for the new experiments.



Special hydrodynamic shock codes have been developed in both Russia and

at Rensselaer to support and interpret the ORNL experiments. These

computer codes indicated that the peak gas temperatures and densities in

the ORNL experiments were sufficiently high to create fusion reactions.

Indeed, the theoretical shock code predictions of deuterium-deuterium

(D-D) fusion were consistent with the ORNL data.



The research team leaders are all well known authorities in the fields

of multiphase flow and heat transfer technology and nuclear engineering.

Taleyarkhan, a fellow of the American Nuclear Society (ANS) and the

program's director, held the position of Distinguished Scientist at

ORNL, and is currently the Ardent Bement Jr. Professor of Nuclear

Engineering at Purdue University. Lahey is a fellow of both the ANS and

the American Society of Mechanical Engineers (ASME), and is a member of

the National Academy of Engineering (NAE). Nigmatulin is a visiting

scholar at Rensselaer, a member of the Russian Duma, and the president

of the Bashkortonstan branch of the Russian Academy of Sciences (RAS).

Block is a fellow of the ANS and is the longtime director of the

Gaerttner Linear Accelerator (LINAC) Laboratory at Rensselaer. The

bubble fusion research program was supported by a grant from the Defense

Advanced Research Projects Agency (DARPA).









- Dan Strom



The opinions expressed above, if any, are mine alone and have not been

reviewed or approved by Battelle, the Pacific Northwest National

Laboratory, or the U.S. Department of Energy.



Daniel J. Strom, Ph.D., CHP

Environmental Technology Directorate, Pacific Northwest National

Laboratory

Mail Stop K3-56, PO BOX 999, Richland, Washington 99352-0999 USA

Overnight: Battelle for the U.S. DOE, 790 6th St., Richland WA 99352

ATTN: Dan Strom K3-56

Telephone (509) 375-2626 FAX (509) 375-2019 mailto:strom@pnl.gov

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