Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists tackle long-standing questions about plutonium

07.06.2006


Scientists have gone a long way to solving a question about the nature of plutonium that has remained a mystery since the Manhattan Project.


A plutonium-gallium alloy ingot reclaimed from a nuclear weapon.



Plutonium behaves like no other element in nature. The bonding of its electrons causes its crystal structure to be uneven, similar to a mineral, and the nucleus is unstable, causing the metal to spontaneously decay over time and damage the surrounding metal lattice.

A plutonium-gallium alloy ingot reclaimed from a nuclear weapon.


First batches of the metal were too brittle to machine due to the mineral-like structure of the crystal. In order to make the metal machinable, the high-temperature, high-symmetry cubic structure of plutonium needed to be retained to room temperature.

Scientists during the Manhattan Project achieved this by adding a small amount of gallium.

There was never a clear explanation as to why gallium stabilized the ductile cubic structure over the low-symmetry mineral-like structure; they just did it and it worked, said Kevin Moore, a staff scientist in the Materials Science and Technology Division at Lawrence Livermore National Laboratory.

For the first time, researchers have determined why gallium works. In pure plutonium, the bonds between Pu atoms are very uneven, causing the metals high propensity to adopt a low-symmetry structure. However, when a gallium atom is put in the plutonium lattice, it causes the bonds to become more uniform and thus leads to the high-symmetry cubic structure.

Gallium evens out the plutonium bonds, Moore said. The calculations strongly illuminate why gallium stabilizes the machinable cubic structure to room temperature.

Through a series of calculations, Moore and his Livermore colleagues, Per Söderlind and Adam Schwartz, and David Laughlin of Carnegie Mellon University have produced results that appear in the May 26 online edition of Physical Review Letters.

The team next proposes to test their calculations in the laboratory.

Founded in 1952, Lawrence Livermore National Laboratory has a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy’s National Nuclear Security Administration.

Anne Stark | EurekAlert!
Further information:
http://www.llnl.gov

More articles from Physics and Astronomy:

nachricht Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>