Nuclear physics of the dynamic origin of the elements

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Thanks to new observations and greatly enhanced simulation capabilities, nuclear astrophysics has recently discovered that the puzzle still surrounding the origin of many elements is likely due to their dynamic and violent origin in stellar nuclear production sites that defy simple approaches. In the past few years such dynamic scenarios have been identified to explain e.g. the abundances of the most metal-poor stars, as well as the origin of odd-Z elements, in the galactic chemical evolution of the Milky Way. These scenarios include the intermediate neutron-capture process (i-process) in convective interactions of the H and He shells in rapidly accreting white dwarfs or very metal-poor massive stars, or the convective-reactive nucleosynthesis in the merger of the O- and C-burning shells in massive stars. The recent discovery of gravitational waves from neutron-star mergers and the associated observation of the electro-magnetic counterpart of the light likely from decaying unstable species has firmly established the role of dynamic nucleosynthesis for the rapid neutron-capture process (r-process). The importance of these dynamic nuclear production sites has put forth the need for improved nuclear data for unstable species. The short lifetime of radioactive isotopes has seriously limited in the past the experimentally available information on nuclear data, such as cross sections and nuclear masses. Now, with new experimental facilities such as ARIEL at TRIUMF, FRIB and other facilities in Europe huge progress can be made by targeted, high-impact experiments that provide critical nuclear data to enable astrophysics simulation to distinguish between different scenarios of the dynamic origin of the elements in stars and stellar explosions.    This project will combine the astrophysics and nucleosynthesis simulation capabilities of an experienced senior researcher who will work on four projects, each of which focusses on a different dynamic nucleosynthesis environment. Each of these projects will be carried out with graduate students who will spend one half of the period of the project (three years) on this simulation and modelling effort, while the other half will be dedicated to nuclear physics experiments in the corresponding area. In each of these areas nuclear data, as it becomes available, will be implemented into the latest generation of astrophysical simulation and confronted with observations to maximize the impact of the nuclear physics experiments. Other than the science outcome, another main goal of this project is to transfer the skill of nuclear physics impact studies for astrophysics applications to a new generation of young nuclear physics researchers. This skill is relatively rare, yet the impact of the Canadian and international nuclear astrophysics programs involving radioactive beams critically depends on this type of activity.