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 Molecule flash mob
19.01.2017 | Technische Universität Wien

nachricht Magnetic moment of a single antiproton determined with greatest precision ever
19.01.2017 | Johannes Gutenberg-Universität Mainz

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>