Theos-Talk Archives (November 2005 Message tt00228)

First step toward making "little sun" as limitless energy source 
reported

Nov. 25, 2005
Special to World Science

Scientists say they have taken a first step towards making a sort of 
miniature sun that could serve as a virtually limitless energy source.

The project, at Lawrence Livermore National Laboratory in California, 
would involve squeezing atoms until they merge, releasing energy in 
the process. This process, called nuclear fusion, is what makes the 
Sun shine. 



 
In nuclear fusion as it occurs on the Sun, an atom of deuterium and 
an atom of hydrogen are forced together by high pressure into one 
atom, which then quickly releases a neutron. During the process, a 
small part of the mass of the original particles is converted into 
energy. (Image courtesy U.S. Heavy-Ion Fusion program)

----------------------------------------------------------------------
----------
 
Scientists have been working for decades to harness nuclear fusion 
because it's thought that this would provide a clean, safe 
alternative to existing nuclear power plants. But technical hurdles 
and at least one widely publicized false claim of success have beset 
the research.

The Livermore project would use the world's most powerful laser, 
called the National Ignition Facility and which is currently under 
construction, to heat a small, enclosed space.

In that space, scientists would place a container holding a frozen 
sample of a type of hydrogen. The heat would expand the container, 
forcing its contents into a smaller and smaller space until the atoms 
merge.

Livermore scientists reported in a new paper that in a test run 
without the container of hydrogen, the enclosed space generated 
enough energy in the form of X-rays to produce the necessary heating 
to make the project work.

The heat wasn't sufficient for fusion, as only four laser beams were 
used of the 192 that would eventually come into play, researchers 
said. But the amount of energy generated matched computer simulations 
developed for the project, showing the work was on track, they added.

The findings were published in the Nov. 18 issue of the research 
journal Physical Review Letters.

It could take decades of additional work to convert this promising 
start into working power plants, said the laboratory's Eduard Dewald. 
Fusion will be achieved "hopefully in 2010," he said; further 
research will involve making the process efficient and quickly 
repeatable enough to generate power on a mass scale.

Existing nuclear power plants extract energy from atoms by splitting 
them up, a process called fission. The new research, by contrast, 
does it by forcing them together, a process known as fusion. 

The reason these opposite processes can achieve the same result is 
that the types of atoms are different. Some types release energy when 
they're forced together, others do so when they're split up. Fusion 
energy research employs variants of hydrogen atoms called deuterium 
and tritium.

Another line of research toward harnessing fusion energy involves 
using magnetic fields rather than laser heating to confine the atoms. 
Last summer, an international group of scientists and politicians 
agreed to build an experimental fusion reactor in Cadarache, France, 
using that strategy. 
* * *

Send us a comment on this story, or send it to a friend

 

WORLD SCIENCE
  
 
http://www.world-science.net/othernews/051123_fusionfrm.htm
WORLD SCIENCE