Rare Isotopes and the Synthesis of the Elements in Cosmic Explosions

日期:2016-12-14 阅读:889


There is much we do not know about how nature created the chemical elements. Especially the origin of heavy elements like gold, platinum, or uranium is a long standing mystery.  Long suspected sources of heavy elements are violent astrophysical events such as supernova explosions or colliding neutron stars. Very unstable atomic nuclei, so called rare isotopes, play a key role in these environments as stepping stones for the nuclear reactions to transform light elements into heavier ones. Despite their fleeting existence, often for less than a fraction of a second, the properties of these rare isotopes at the subatomic scale imprint themselves onto the observed properties of stellar explosions, and define the characteristic chemical composition of the universe. With new rare isotope beam facilities such as the Facility for Rare Isotope Beams at Michigan State University, these very same isotopes can now for the first time be created in the laboratory, and the element creating nuclear processes can be studied on earth. At the same time, advances in astronomy have opened up a view of the entire chemical history of our Galaxy from the very first stars to today, and the first detection of gravitational waves opens up a new window to study the violent astrophysical events that may have created the elements. With these developments, and with new advanced computer models of stellar explosions, we are now at the verge of finally solving the mystery of the origin of the elements. 


Hendrik Schatz is a University Distinguished Professor at the Department of Physics and Astronomy and the National Superconducting Cyclotron Laboratory at Michigan State University. He serves as Director of the Joint Institute for Nuclear Astrophysics Center for the Evolution of the Elements (JINA-CEE), a multi-institutional NSF Physics Frontiers Center and is a Fellow of the American Physical Society. After receiving his PhD at the Ruprecht-Karls Universitaet Heidelberg, Germany for work largely performed at the University of Notre Dame he held post-doctoral appointments at UC Berkeley and GSI, Germany before joining the faculty at Michigan State University in 1999. His research interests are experimental and theoretical studies of nuclear reactions in astrophysical environments that involve unstable isotopes, such as X-ray bursts, neutron stars, and supernovae. He is currently the Project Manager for the construction of the recoil separator SECAR, which will measure the rates of astrophysical nuclear reactions at the future Facility for Rare Isotope Beams (FRIB) under construction at Michigan State University. 

Host: Prof. Yang Sun


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