Two years ago, Rusi Taleyarkhan at Oak Ridge and colleagues made the amazing claim that they had found evidence for neutron emission and tritium production in chilled, deuterated acetone when blasted with sound to produce sonoluminescence (CERN Courier May 2002 p11). This was greeted with much scepticism, but in response to comments that suggested the need for various improvements, Taleyarkhan, now also at Purdue, and his team perfor- med a more careful version of the experiment, which seems to confirm the earlier results.
This time the researchers report a "large and statistically significant" emission of neutrons with energies of 2.5 MeV and below, at a rate of up to around 4 x 105 neutrons per second. They also measured the rate of tritium production and found that this was consistent with the observed neutron emission rate, assuming it to be due to deuterium-deuterium fusion. Control experiments using normal acetone did not result in significant tritium activity or in neutron or gamma-ray emissions. Now it remains to be seen how the physics community will respond to these results.
Further reading
R P Taleyarkhan et al. 2004 Phys. Rev. E 69 036109.