Sunday, November 14, 2010

cold energy-a viable energy source

A revolution in nuclear science appears to be unfolding, offering prospects of a 'third route' to nuclear energy besides fission and thermonuclear fusion, one of India's top nuclear physicists and cold fusion pioneers said Saturday.

'Prospects of developing table-top nuclear power packs generating power in the range of 10 kW to 100 kW loom on the horizon,' said Mahadeva Srinivasan, a former associate director of physics at the Bhabha Atomic Research Centre (BARC) and a key figure in the design of 'Purnima' - India's first fast reactor.

The private industry can potentially take a leading role in mass manufacturing and marketing these power packs, he added.

Speaking on the emerging field of 'condensed matter nuclear science' at the National Institute of Advanced Studies (NIAS) here, Srinivasan said 'unbelievable, multi-body nuclear reactions appear to be taking place in simple experimental configurations, involving the nuclei of palladium'.

These reactions, formerly called cold fusion, are now referred to as low energy nuclear reactions (LENR) and the field, as a whole, is called condensed matter nuclear science, he said.

Achieving fusion at room temperature was considered impossible until 1989 when Martin Fleischmann and Stanley Pons at the University of Utah (US) startled scientists with their tabletop experiment.

The two connected a battery to a pair of palladium electrodes immersed in a jar of water containing deuterium (a heavier form of hydrogen) and showed their electrolytic cell produced heat energy in excess of what was consumed. They claimed that origin of the energy was nuclear and that deuterium nuclei were being packed into the palladium's molecular lattice in such a way for fusion to take place.

Later, it was shown by other groups and Srinivasan's experiments at BARC in early 1990s that the reaction produced tritium as well as helium, indicating that cold fusion was real.

Though the subject of cold fusion got entangled in a worldwide scientific controversy and the BARC experiments were shut down in the early 1990s, great strides have been made in this field in the last few years, Srinivasan said.

Listing some of the recent experiments in low energy nuclear reactions, he said the results clearly showed 'that science has indeed stumbled upon a new route to tapping the energy locked in the nucleus'.

Srinivasan said that it has by now been clearly established that heat is generated through nuclear reactions that can be made to occur when deuterium is 'heavily' loaded into certain selected metals like palladium, titanium, and nickel.

The experiments were found to give more reproducible results when the metals used were in the form of nano-powders, he said.

A new technique was pioneered by Yoshiaki Arata of Osaka University who passed deuterium gas through a matrix containing nano-powders of palladium and nickel and the low energy nuclear reactions in such a set-up produced excess heat 'for days at a stretch,' Srinivasan said.

Clearly something 'magical' is happening within the ordered atomic lattice, he said. 'All this is totally new physics, totally unexpected. By all accounts, radiationless nuclear reactions, starting from stable atoms and ending in stable atoms, seem to be taking place,' he said.

Srinivasan said the nuclear energy released appears to be transferred directly to the lattice as atomic vibrations (called 'phonons'). 'Incredible elemental transmutations appear to be occurring. In some LENR devices, power densities (watts per gm of palladium fuel) comparable to that in nuclear power plants have already been demonstrated,' he said.

'It is heartening to note that in the light of overwhelming new experimental evidence, the negative impression (on cold fusion) is slowly yielding place to one of cautious curiosity,' he said.

Srinivasan said that currently about 300 scientists are engaged in research in this field of low energy nuclear reactions primarily in the US, Italy, France, Russia, Ukraine, Japan, China and Israel.

'It is our firm conviction that this novel 'third' route to tapping nuclear energy can have a great impact on the future scenario of energy security in India,' Srinivasan said.

'Whether this could become a reality depends on whether Indian science and private entrepreneurship is going to jump on the bandwagon and lead the way or sit back and let some other country, possibly China, to race ahead and become the world leaders in the field,' he said