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

Researchers Report Bubble Fusion Results Replicated

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.

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