A tabletop atomic accelerator at Rennselaer Polytechnic Institute produces nuclear fusion at room temperature, researchers claim.
The device, which uses two opposing crystals to generate a powerful electric field, could lead to a portable, battery-operated neutron generator for nondestructive testing and detecting explosives and scanning luggage at airports.
The demonstration confirms an earlier experiment conducted at UCLA, while offering substantial improvements over the original design. "Our study shows 'crystal fusion' is a mature technology with considerable commercial potential," says 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 could produce even more neutrons."
The 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 explains.
At the heart of the accelerator 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 taken place.
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," says Jeffrey Geuther, a graduate student at Rensselaer and lead author of the paper. "And our setup 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 keV needed for medical imaging," he says.
"Our device can produce about 200 keV, which could meet these requirements and also be enough to penetrate several millimeters of steel."