Breakthrough brings cold fusion a step closer

Researchers at Rensselaer Polytechnic Institute have developed a tabletop atomic accelerator that produces nuclear fusion at room temperature.

The device, which uses two opposing crystals to generate a powerful electric field, could lead to "a portable, battery-operated neutron generator for a variety of applications, from non-destructive testing to detecting explosives and scanning luggage at airports".

The successful demonstration provides confirmation of an earlier experiment conducted at the University of California, Los Angeles (UCLA), while offering substantial improvements over the original design.

"Our study shows that 'crystal fusion' is a mature technology with considerable commercial potential," said Yaron Danon, associate professor of mechanical, aerospace and nuclear engineering at Rensselaer.

"This new device is simpler and less expensive than the previous version, and it has the potential to produce even more neutrons."

The new study verified that pyroelectric crystals are a viable means of producing nuclear fusion, and that commercial applications may be closer than originally thought, according to Danon.

"Nuclear fusion has been explored as a potential source of power, but we are not looking at this as an energy source right now," he explained.

Danon said that the device is essentially a tabletop particle accelerator. At its heart are two opposing pyroelectric crystals that create a strong electric field when heated or cooled.

The device is filled with deuterium gas, a more massive cousin of hydrogen with an extra neutron in its nucleus. The electric field rips electrons from the gas, creating deuterium ions and accelerating them into a deuterium target on one of the crystals.

When the particles smash into the target, neutrons are emitted, which is the telltale sign that nuclear fusion has occurred.

A research team led by Seth Putterman, professor of physics at UCLA, reported on a similar apparatus in 2005, but two important features distinguish the new device.

"Our device uses two crystals instead of one, which doubles the acceleration potential," said Jeffrey Geuther, a graduate student in nuclear engineering at Rensselaer and lead author of the paper.

"And our set-up does not require cooling the crystals to cryogenic temperatures, an important step that reduces the complexity and the cost of the equipment."

The concept could also lead to a portable X-ray generator, according to Danon. "There is already a commercial portable pyroelectric X-ray product available, but it does not produce enough energy to provide the 50,000 electron volts needed for medical imaging," he said.

"Our device is capable of producing about 200,000 electron volts, which could meet these requirements and could also be enough to penetrate several millimetres of steel."