Scientists Looking at the Very Small to Shed Light on One of The Great Questions of Physics

    CAPE TOWN, SOUTH AFRICA, May 03, 2012 /24-7PressRelease/ -- "How were the heavy elements from iron to uranium made?" Discover magazine identified this as one of the greatest unsolved questions of physics in February 2002. Many of the elements are believed to be produced in stars and supernovae throughout the universe. Now, scientists have come one step closer to answering this question.

The 18-member team from seven US American, South African, and European laboratories and universities was led by Dr. Mathis Wiedeking of iThemba LABS (South Africa) and Lawrence Livermore National Laboratory (California, USA). The scientists, for the first time, independently confirmed the existence of an enhancement feature in the decay pattern by investigating the radioactive disintegration of nuclei. Just as for many scientific discoveries, the existence of this enhancement has been the topic of a decade-long debate in part because it would dramatically alter the production of the elements in the hot and dense cosmic environments where they are made.

The team's observation followed an experiment where particles were smashed together to create new nuclei. The decay products from these nuclei, such as gamma radiation which originate from deep within them, are then studied using arrays of advanced detector systems. From this a wealth of information can be extracted such as the effects that influence overall reaction rates in astrophysical environments which are present during a supernova event.

The observed feature manifests itself through an increase in the ability of nuclei to absorb and emit light characteristic of the environments where the elements are formed. With the existence of the enhancement now confirmed, it has become clear that laboratory-based experiments must occur in the same settings as where they take place in the cosmos if they are to best answer the question of how the elements are formed.

To pursue this goal the international team of scientists will perform experiments using tiny pieces of star matter which is created using the world's most energetic laser at the National Ignition Facility at Lawrence Livermore National Laboratory in California. The information garnered from these experiments, may significantly improve our understanding of the elemental abundances observed here on earth and elsewhere in the universe.

The results were published in the journal Physical Review Letters, Vol.108, No.16, 162503 by the American Physical Society.

iThemba LABS is an accelerator research laboratory funded by the National Research Foundation of South Africa. The facility provides accelerated particle beams for research, cancer treatment and isotope production.

Website: http://www.tlabs.ac.za

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