New! Sign up for our free email newsletter.
Science News
from research organizations

Z-Beamlet Image Shows Z Evenly Compresses Pellet

Date:
September 6, 2001
Source:
Sandia National Laboratories
Summary:
To create high-yield nuclear fusion that will ultimately produce cheap electric power from sea water, researchers must be able to evenly compress a BB-sized pellet so that its atoms are forced to fuse.
Share:
FULL STORY

ALBUQUERQUE, N.M. — To create high-yield nuclear fusion that will ultimately produce cheap electric power from sea water, researchers must be able to evenly compress a BB-sized pellet so that its atoms are forced to fuse.

In its first try as a Sandia National Laboratories diagnostic tool, the third-biggest laser on earth, Z-Beamlet, confirmed that Sandia’s Z machine — the most powerful laboratory producer of X-rays in the world —spherically compressed a simulated fusion pellet during a firing, or “shot,” of the giant accelerator.

“The beam compressed the pellet by a factor of 2,” says project leader John Porter, “and demonstrated an encouraging uniformity. Our results show we’re moving in the right direction.”

Uniform 3-D compression is an essential step in creating controlled nuclear fusion. It means that almost none of the X-ray energy delivered to the pellet squirted uselessly away. Weapons simulation work (the alternative to nuclear testing) conducted on supercomputers by Sandia for the US Department of Energy is expected to benefit from data from high-yield explosions, as should, further down the pike, energy production.

Until now, Z researchers had to be content with electronic images of smoother and smoother Z pinches — the tool of compression. The pinch — a vertical magnetic cylinder — with increasing smoothness impels ions of tungsten toward its vertical axis at a considerable fraction of the speed of light. But knowing that the tool is good and getting better isn’t definite information about the pellet upon which the tool is operating. Only direct data is entirely convincing, or, to put it in a more homely way, seeing is believing.

Z-Beamlet images the pellet in a kind of giant dental X-ray, says Porter. In a burst of energy only a fraction of a billionth of a second long, it takes a snapshot by creating a shadow on a piece of X-ray film placed behind the BB-sized pellet inside the central chamber of the firing Z machine. The shadow, like the picture taken of a tooth, accurately depicts what is going on in the “mouth” of Z.

The comparison with the dental X-ray process is closer than it might appear. The laser’s light itself is not used to create the pellet image. Higher frequencies of light are needed to produce better information. So the beam, after traveling horizontally 75 yards from a former warehouse adjacent to the Z building, is turned downward 90 degrees into the maw of Z, where it is focused to a small spot about the diameter of a human hair.

Because the duration of the pulse is about 300 picoseconds — about enough time for light, which can travel around the earth seven times in a second, to travel about four inches — an extremely powerful beam is created because of the short time duration in which its energy is expended. The powerful beam striking the metal plate causes the plate to release X-rays. It is these X-rays, as they emanate from a single point, that have the accuracy and intensity to image the pellet.


Story Source:

Materials provided by Sandia National Laboratories. Note: Content may be edited for style and length.


Cite This Page:

Sandia National Laboratories. "Z-Beamlet Image Shows Z Evenly Compresses Pellet." ScienceDaily. ScienceDaily, 6 September 2001. <www.sciencedaily.com/releases/2001/09/010905071801.htm>.
Sandia National Laboratories. (2001, September 6). Z-Beamlet Image Shows Z Evenly Compresses Pellet. ScienceDaily. Retrieved April 15, 2024 from www.sciencedaily.com/releases/2001/09/010905071801.htm
Sandia National Laboratories. "Z-Beamlet Image Shows Z Evenly Compresses Pellet." ScienceDaily. www.sciencedaily.com/releases/2001/09/010905071801.htm (accessed April 15, 2024).

Explore More

from ScienceDaily

RELATED STORIES