Nuclear Astrophysics at TRIUMF-ISAC: Stellar Burning Reaction Studies with DRAGON and TUDA

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It is presently accepted that most of the chemical elements heavier than boron were produced in stars through nuclear reactions involving stable and radioactive nuclei and radioactive decays. Astrophysical models of the various stages of stellar evolution (e.g. quiescent burning, or explosive processes as seen in novae and supernovae) that contribute to this nucleosynthesis have recently become more advanced, enabling good predictions of astronomical observables. Examples of these are isotopic abundances frozen into dust grains that make up our solar system, gamma-ray fluxes from synthesized long-lived radionuclides, optical or x-ray luminosity etc. These quantities can be compared with astronomical observations, including those from orbiting gamma ray observatories or laboratory measurements on meteoric grains. This comparison is a powerful tool in the field of astrophysics and cosmology, giving us the most direct imaging technique of the nuclear processes inside stars and their explosions. In order to improve the models, and therefore advance our understanding of these powerful and mysterious stellar events, a precise knowledge of the nuclear reactions involved in energy generation and nucleosynthesis is required. ******The Nuclear Astrophysics program at TRIUMF-ISAC addresses these issues by making direct and indirect measurements of astrophysically important nuclear reactions with radioactive and stable accelerated ion beams. This is primarily done at the well-known DRAGON recoil separator facility, and at the TUDA charged particle array facility. In addition, the program participants engage in state-of-the art stellar model studies (using MESA-NuGrid) and ab-initio nuclear theory calculations.******Our proposal will request funding for the continued operation and development of the DRAGON program, including the hiring of 3 Post-Doctoral Research Associates, the existence of which has been the foundation of DRAGON's past success. We also request continuation of training of highly-qualified personnel such as Graduate Students, to make the cutting-edge measurements for the astrophysics cases mentioned above. We will also request one Post-Doctoral Research Associate for the TUDA program. Postdocs will also work using the DSL and SHARC facilities, performing complimentary research in a comprehensive nuclear astrophysics program. ********