Nuclear Astrophysics is, basically, the physics of stars. How the stars form, how they generate the energy that powers them, and how they reach their end--sometimes quietly, at other times in cataclysmic explosions--are the questions this field seeks to understand and provide answers to.
The primary aim of the proposed work is to attempt to understand the nuclear reactions that are critical to the energy generation in stars and to the formation of most of the heavy elements that are observed in the Universe. We will use the particle accelerators available in our laboratory, and at laboratories around the world, to investigate specific nuclear reactions that are critical to our understanding of these phenomena, in particular the process of synthesis of heavy elements in the stellar environment. In a holistic approach, we will look at the rate at which certain reactions proceed and the impact these rates have on the generation of higher mass nuclei, measure the atomic masses of the nuclei that are crucial to this process, investigate the theoretical underpinnings of these reactions, and identify avenues of further research. We will also study bulk properties of nuclear matter to better understand the formation of neutron stars and the probability of supernova explosions in the final moments of a star's existence. In a novel approach to these investigations, we will use the techniques of accelerator mass spectrometry (widely known for its use in radiocarbon dating) to identify very rare processes occurring in astrophysical reactions. Another aspect of this work is to investigate some exotic aspects of the quantal motion of the atomic nuclei. The primary aim of these investigations of the "structure" of the atomic nuclei is to understand the fundamental way in which the constituents of the atomic nucleus--the protons and neutrons--interact with each other, and how these interactions lead to the observed nuclear properties. A number of the proposed studies of nuclear structure have direct implications on the astrophysical phenomena the investigation of which constitute the main body of this project.
A very important component of the proposed work is training of young scientists. A large number of graduate students and undergraduate students will be involved with this work, in addition to a few postdoctoral fellows. These young cientists will, in the future years, form the pool of highly-trained personnel, so crucial not only to the continuing leadership of the United States in frontier fields of science and technology, but also to our efforts in defense and homeland security.
