Tin-100, a doubly magic nucleus

22-Jun-2012

Thomas Faestermann / TUM

A view of the experiment at the GSI from a perspective against the beam direction. The fragments are stopped at the center of a “hedgehog” of 105 liquid nitrogen-cooled gamma ray detectors, where the precise time point of the beta decay and the released decay energy are measured.

A few minutes after the Big Bang the universe contained no other elements than hydrogen and helium. Physicists of the Technische Universitaet Muenchen (TUM), the Cluster of Excellence “Universe” and the Helmholtz Center for Heavy Ion Research (GSI) have now succeeded in producing tin-100, a very instable yet important element for understanding the formation of heavier elements.

A few minutes after the Big Bang the universe contained no other elements than hydrogen and helium. Physicists of the Technische Universitaet Muenchen (TUM), the Cluster of Excellence “Universe” and the Helmholtz Center for Heavy Ion Research (GSI) have now succeeded in producing tin-100, a very instable yet important element for understanding the formation of heavier elements. The researchers report on their results in the current edition of the scientific journal Nature.

Stable tin, as we know it, comprises 112 nuclear particles – 50 protons and 62 neutrons. The neutrons act as a kind of buffer between the electrically repelling protons and prevent normal tin from decaying. According to the shell model of nuclear physics, 50 is a “magic number” that gives rise to special properties. Tin-100, with 50 protons and 50 neutrons, is “doubly magic,” making it particularly interesting for nuclear physicists.

Shooting xenon-124 ions at a sheet of beryllium, the international team headed by physicists from the TU Muenchen, the Cluster of Excellence Origin and Structure of the Universe and the GSI in Darmstadt succeeded in creating tin-100 and analyzing its subsequent decay. Using specially developed particle detectors, they were able to measure the half-life and decay energy of tin-100 and its decay products. Their experiments confirmed that tin-100 has the fastest beta decay of all atomic nuclei, as previously predicted by theoretical physicists.

A repeat of the experiment is slated for the near future at the RIKEN research center in Japan. The beam intensity at RIKEN is higher in the mean time, allowing even more precise measurements. The aim of the research work is to improve the understanding of processes in the formation of heavy elements during explosions on the surface of compact stars. In addition, the researchers hope to draw conclusions on the neutrino mass from the measurements.

This work was supported by the BMBF, by the GSI, by the DFG-Cluster of Excellence Origin and Structure of the Universe, by the EC within the FP6 through I3-EURONS and by the Swedish Research Council.

Original publication:

Superallowed Gamow-Teller Decay of the Doubly Magic Nucleus Sn-100, Christoph B. Hinke et al., Nature, 21. Juni 2012

Facts, background information, dossiers
  • tin
  • GSI
  • TU München
More about TU München
  • News

    Chocolate physics: How modeling could improve 'mouthfeel'

    Lecithin plays a vital role in the production of chocolate and many other foods. It's never been clear how this ingredient works on a molecular level, and confectioners have relied on observational methods to perfect their recipes. Now, scientists have shown how the field of molecular dynam ... more

    Mini X-ray source with laser light

    Physicists from Ludwig-Maximilians-Universität, the Max Planck Institute of Quantum Optics and the TU München have developed a method using laser-generated X-rays and phase-contrast X-ray tomography to produce three-dimensional images of soft tissue structures in organisms With laser light ... more

    Record-breaking magnetic shielding for high-precision experiments

    Magnetic fields easily penetrate matter. Creating a space practically devoid of magnetic fields thus presents a great challenge. An international team of physicists has now developed a shielding that dampens low frequency magnetic fields more than a million-fold. Using this mechanism, they ... more

More about GSI
Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE