Scientist at Oak Ridge National Laboratory may have found a cheap way to cause hydrogen atoms to fuse. (same article here)
The researchers expose the clear canister of liquid to pulses of neutrons every five milliseconds, or thousandths of a second, causing tiny cavities to form. At the same time, the liquid is bombarded with a specific frequency of ultrasound, which causes the cavities to form into bubbles that are about 60 nanometers – or billionths of a meter – in diameter. The bubbles then expand to a much larger size, about 6,000 microns, or millionths of a meter – large enough to be seen with the unaided eye.
"The process is analogous to stretching a slingshot from Earth to the nearest star, our sun, thereby building up a huge amount of energy when released," Taleyarkhan said.
Within nanoseconds these large bubbles contract with tremendous force, returning to roughly their original size, and release flashes of light in a well-known phenomenon known as sonoluminescence. Because the bubbles grow to such a relatively large size before they implode, their contraction causes extreme temperatures and pressures comparable to those found in the interiors of stars. Researches estimate that temperatures inside the imploding bubbles reach 10 million degrees Celsius and pressures comparable to 1,000 million earth atmospheres at sea level.
At that point, deuterium atoms fuse together, the same way hydrogen atoms fuse in stars, releasing neutrons and energy in the process. The process also releases a type of radiation called gamma rays and a radioactive material called tritium, all of which have been recorded and measured by the team. In future versions of the experiment, the tritium produced might then be used as a fuel to drive energy-producing reactions in which it fuses with deuterium.
Whereas conventional nuclear fission reactors produce waste products that take thousands of years to decay, the waste products from fusion plants are short-lived, decaying to non-dangerous levels in a decade or two. The desktop experiment is safe because, although the reactions generate extremely high pressures and temperatures, those extreme conditions exist only in small regions of the liquid in the container – within the collapsing bubbles.
The ability to sustain nuclear fusion could provide a way to produce enormous quantities of energy. If this could be done very cheaply then the age of fossil fuels would come to an end.
Although no one has tried repeating the latest work, Lee Riedinger, deputy director for science and technology at Oak Ridge, says that, it went through an "extraordinary level of review" before being accepted for publication by Physical Review E.
For decades, physicists have dreamed of harnessing the ferocious alchemy of the Sun as a clean, limitless energy source. Most experiments have been conducted in giant, expensive reactors using magnetic fields to confine the ultrahot gases.
In contrast, the new experiment, which cost less than $1 million, uses the power of sound to create energy comparable to the inside of stars.
Hopefully granting agencies will allocate the money needed to for other labs to check this result. If this result holds up then our future could take a really big turn.
|Share |||Randall Parker, 2004 March 04 03:13 AM Energy Tech|