Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Out-of-shape nuclei

22.08.2011
Adding neutrons to synthetic atoms can drastically alter the shape of their nuclei and affect their stability

To probe the evolution of atomic nuclei with different shape —a factor which affects atomic stability—a large team of international researchers has added neutrons to zirconium atoms and revealed the possibility of very unusual shapes. “The shape of a nucleus reflects the symmetry of its quantum state,” explains team member Hiroyoshi Sakurai from the RIKEN Nishina Center for Accelerator-Based Science in Wako. This result helps us to understand how many neutrons are needed for the most stable nuclei.

Most atoms can exist in one of several alternative forms called isotopes, depending on the number of neutrons in their core. Naturally occurring, stable, atoms tend to have between 1 and 1.5 neutrons per proton. However, synthetically generated atoms with higher neutron–proton ratios can reveal much about changes within an atomic nucleus.

The protons and neutrons in a nucleus usually form arrangements of concentric spherical shells. In some cases, however, the outermost particles exist further from the center than normal. This can lead to nuclei that are wider than they are long. Just as atoms with a specific number of protons can exist as different isotopes, atoms with a specific number of protons and neutrons can exist as different nuclear isomers—nuclei with different shapes. “By measuring the shape of nuclei, we are probing the internal symmetry in the nucleus—the so-called shell structure,” explains Sakurai.

At the Radioactive Isotope Beam Factory in Japan, operated jointly by RIKEN and The University of Tokyo, the researchers experimented with zirconium atoms that have 40 protons and, in their stable form, between 50 and 52 neutrons. They created zirconium atoms with as many as 68 neutrons through collisions between uranium and beryllium atoms. After filtering isotopes from the remnants of the collision, they measured the rate of decay of beta and gamma radiation emitted by the quickly decaying, unstable synthetic atoms. The measurements showed that these nuclei changed shape from spherical to oblate.

The degree of deformation of the zirconium nuclei increased as Sakurai and colleagues added more neutrons, but this trend stopped when they reached 64 neutrons. This result raises the intriguing prospect of a tetrahedral-shaped isomer of zirconium-108—an isotope with 68 neutrons—which has been predicted previously by other researchers. However, further work is needed to verify this.

“We next hope to gain further insight into the evolution of nuclear isomers by extending our study to strontium atoms,” Sakurai says.

The corresponding author for this highlight is based at the Radioactive Isotope Physics Laboratory, RIKEN Nishina Center for Accelerator-Based Science

Reference:
Sumikama, T., Yoshinaga, K., Watanabe, H., Nishimura, S., Miyashita, Y., Yamaguchi, K., Sugimoto, K., Chiba, J., Li, Z., Baba, H. et al. Structural evolution in the neutron-rich nuclei 106Zr and 108Zr. Physical Review Letters

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

Further reports about: Out-of-shape RIKEN Radioactive atomic nuclei isotopes zirconium atom zirconium atoms

More articles from Physics and Astronomy:

nachricht SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

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

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>