Nucleosynthesis in Star
In the universe, various and numerous types of elements exists, such as gold, silver, copper, iron, and uranium. But why do these elements exist in the universe? The key to solving this question is in the evolution of the stars in cosmic hisrory. Through various processes from 13.8 billion years ago, various elements in the universe have been created with protons and neutrons. It is a so-called alchemy of the universe. Is considered to occur by nuclear reaction called rapid neutron capture process (r-process), it would not be made only in extreme environments such as supernova explosions of stars, and heavy elements as uranium and lead have been synthesized. Nuclei related to the r-process is very neutron-rich, and even now it is extremely difficult to obtain their properties experimentally. Generally, nuclear reactions is governed by reaction Q value, which is the difference between nucelear masses, therefore nuclear mass theory for unknown nuclei becomes important. In addition, effects of nuclear fission in the r-process calculations had not been much neglected until recently. Currently, we have investigated the effect of fission in the r-process based on the results of nuclear fission in actinides and superheavy nuclei,movie of r-process nucleosynthesis (GIF file) (Enthropy S=200, GIF file)
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GOTO HOMEPAGE of Hiroyuki Koura