A Franco-Japanese experiment in search of nuclear magic numbers

November 10, 2015, CEA

A Franco-Japanese research team including researchers from CEA, CNRS, Université Paris-Sud and Université de Strasbourg has designed an experiment to study highly unstable atomic nuclei. Initial results are published in the 3 November 2015 issue of Physical Review Letters. This research advances our understanding of the strong interaction, one of the four fundamental forces of nature, which governs the behavior of matter within atomic nuclei.

Our physical world is governed by four : gravitation, electromagnetism, the weak interaction responsible for radioactive decay, and the strong interaction holding together subatomic particles. The strong nuclear force, derived from the , binds nucleons (protons and neutrons) together within . It is responsible for complex quantum phenomena and the formation of atoms, from lightest to heaviest, in stars.

Certain with specific numbers of neutrons and protons are particularly stable. Nuclear physicists refer to them as 'magic number nuclei'. Understanding the mechanisms responsible for this relative stability and providing a universal description of atomic nuclei remains a challenge for modern theories.

EU framework program and one-of-a-kind Japanese accelerator facility

In order to address this challenge, a new device called MINOS has been developed to measure the spectroscopic properties (i.e. energy levels) of unstable nuclei. This new system is operational since 2014 at the RIKEN Nishina Center's Radioactive Isotope Beam Factory (RIBF), the most advanced facility in the world for producing neutron-rich nuclei and studying previously inaccessible nuclei.

Unraveling the mystery of magic numbers

After 5 years of technical development at CEA and analysis of the first experimental campaign results, the Franco-Japanese research team has just published a first set of results. The first experiment enabled the study of the most neutron-rich chromium and iron nuclei accessible to date. The initial results published in Physical Review Letters question the 'magic' character of N=50 (number of neutrons) for neutron-rich nuclei in this region. MINOS will continue to be used for other experiments, and a wealth of new results is expected. In particular, these experiments should contribute to solving the mystery of magic numbers for unstable nuclei by improving our understanding and modeling of the atomic nucleus.

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1 / 5 (2) Nov 11, 2015
The better definition is "all variations" of only the two particles, "+" and the "-"; whatever they are. Try replacing protons with electrons, leave the neutrons the same. They are only a contained proton and electron. If you wish pick a finite radius as the same for each. Define what happens when the radius goes to zero. Are these particles transparent or totally elastic? What if the number of paired particles gets really, really large? Is the sun or a black hole a radioactive element held together by the sheer cumulative force. Are neutrinos simply a charged particle spinning away from the nucleus under an instability and leaving the radiation due to such a really, really awesome spin an linear motion? Magic numbers? I don't get it! Is it not under what conditions certain numbers are stable? Mass, unnecessary. It's about proximity!
5 / 5 (1) Nov 11, 2015
leave the neutrons the same. They are only a contained proton and electron.

No, they aren't.
Are neutrinos simply a charged particle spinning away from the nucleus

Neutrinos have no charge — hence the name.
not rated yet Nov 11, 2015
I thought this calculation was previously documented from 0 to light and all the wave forms in-between. Hydrogen is a molecule made from a proton and an electron. A waste product produced from dark energy, while the antimatter is absorbed as a mass in dark matter. Pure hydrogen clouds collect into a mass, first stage stars, extremely large, as the center collapses through gravity, the protons and electrons bond creating neutrons, the neutrons bond with electrons and protons, creating more complex atoms until Iron is produced, killing the star. The collapse forces the bonding of more complex structures. Second and third tertiary stars have trace heavy elements within them and cannot collect the size only the mass, forcing them to be smaller. Who wishes to discuss this? Have much more information.

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