Featured Research

from universities, journals, and other organizations

Chemistry: Evidence for a new nuclear 'magic number'

Date:
October 9, 2013
Source:
RIKEN
Summary:
Researchers have come one step closer to understanding unstable atomic nuclei. Scientists have now provided evidence for a new nuclear magic number in the unstable, radioactive calcium isotope 54Ca. They show that 54Ca is the first known nucleus with 34 neutrons (N) where N = 34 is a magic number. 

This image shows the Superconducting Ring Cyclotron (SRC) at RIKEN RIBF, where the experiments were carried out.
Credit: RIKEN

Researchers have come one step closer to understanding unstable atomic nuclei.  A team of researchers from RIKEN, the University of Tokyo and other institutions in Japan and Italy has provided evidence for a new nuclear magic number in the unstable, radioactive calcium isotope 54Ca. In a study published today in the journal Nature, they show that 54Ca is the first known nucleus with 34 neutrons (N) where N = 34 is a magic number. 

Related Articles


The protons and neutrons inside the atomic nucleus exhibit shell structures in a manner similar to electrons in an atom. For naturally stable nuclei, these nuclear shells fill completely when the number of protons or the number of neutrons is equal to the ‘magic’ numbers 2, 8, 20, 28, 50, 82 or 126. 

However, it has recently been shown that the traditional magic numbers, which were once thought to be robust and common for all nuclei, can in fact change in unstable, radioactive nuclei that have a large imbalance of protons and neutrons. In the current study led by David Steppenbeck of the Center for Nuclear Study, the University of Tokyo, the team of researchers focused on 54Ca, which has 20 protons and 34 neutrons in its nucleus. They were able to study this nucleus thanks to the Radioactive Isotope Beam Factory (RIBF) at RIKEN, which produces the highest intensity radioactive beams available in the world.

In their experiment, a radioactive beam composed of scandium-55 and titanium-56 nuclei travelling at around 60% of the speed of light, was selected and purified by the BigRIPS fragment separator, part of the RIBF.  The radioactive beam was focused on a reaction target made of beryllium. Inside this target, projectile fragmentation of the 55Sc and 56Ti nuclei occurred, creating numerous new radioactive nuclei, some in excited states. The researchers measured the energy of the γ rays emitted from excited states of the radioactive nuclei using an array of 186 detectors surrounding the reaction target. 

The results of the experiment indicate that 54Ca’s first excited state lies at a relatively high energy, which is characteristic of a large nuclear shell gap, thus indicating that N = 34 in 54Ca is a new magic number, as predicted theoretically by the University of Tokyo group in 2001.  By conducting a more detailed comparison to nuclear theory the researchers were able to show that the N = 34 magic number is equally as significant as some other nuclear shell gaps. 

“Our new measurement provides key data for the understanding of neutron-rich nuclei and will help pin down the treatment of nuclear forces in systems far from stability,” explains David Steppenbeck. 

“Enriching our knowledge of the structures of highly unstable nuclei and the nucleon-nucleon forces that drive nuclear shell evolution and the appearance or disappearance of the nuclear magic numbers in radioactive nuclei plays an important role in understanding astrophysical processes such as nucleosynthesis in stars,” he adds.


Story Source:

The above story is based on materials provided by RIKEN. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Steppenbeck, S. Takeuchi, N. Aoi, P. Doornenbal, M. Matsushita, H. Wang, H. Baba, N. Fukuda, S. Go, M. Honma, J. Lee, K. Matsui, S. Michimasa, T. Motobayashi, D. Nishimura, T. Otsuka, H. Sakurai, Y. Shiga, P.-A. Sφderstrφm, T. Sumikama, H. Suzuki, R. Taniuchi, Y. Utsuno, J. J. Valiente-Dobσn, K. Yoneda. Evidence for a new nuclear ‘magic number’ from the level structure of 54Ca. Nature, 2013; 502 (7470): 207 DOI: 10.1038/nature12522

Cite This Page:

RIKEN. "Chemistry: Evidence for a new nuclear 'magic number'." ScienceDaily. ScienceDaily, 9 October 2013. <www.sciencedaily.com/releases/2013/10/131009133050.htm>.
RIKEN. (2013, October 9). Chemistry: Evidence for a new nuclear 'magic number'. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2013/10/131009133050.htm
RIKEN. "Chemistry: Evidence for a new nuclear 'magic number'." ScienceDaily. www.sciencedaily.com/releases/2013/10/131009133050.htm (accessed March 3, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Tuesday, March 3, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Forensic Holodeck Creates 3D Crime Scenes

Forensic Holodeck Creates 3D Crime Scenes

Reuters - Innovations Video Online (Mar. 3, 2015) — A holodeck is no longer the preserve of TV sci-fi classic Star Trek, thanks to researchers from the Institute of Forensic Medicine Zurich, who have created what they say is the first system in the world to visualise the 3D data of forensic scans. Jim Drury saw it in operation. Video provided by Reuters
Powered by NewsLook.com
Solar Plane Passes New Test Ahead of World Tour

Solar Plane Passes New Test Ahead of World Tour

AFP (Mar. 2, 2015) — A solar-powered plane made a third successful test flight in the United Arab Emirates on Monday ahead of a planned round-the-world tour to promote alternative energy. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Electric Hydrofoiling Watercraft Delivers Eco-Friendly Thrills

Electric Hydrofoiling Watercraft Delivers Eco-Friendly Thrills

Reuters - Innovations Video Online (Mar. 2, 2015) — The Quadrofoil is a high-tech electric personal watercraft that its makers call a &apos;sports car for the water&apos;. When it hits 10 km/h, the Slovenian-engineered Quadrofoil is lifted above the water onto four wing-like hydrofoils where it &apos;flies&apos; above the surface with minimal water resistance. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Everything You Need To Know About Mobile Payments In 2015

Everything You Need To Know About Mobile Payments In 2015

Newsy (Mar. 2, 2015) — This year, mobile payments might finally catch on. Here are the things you need to know to stay on top of the latest developments. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins