Indirect Methods in Nuclear Astrophysics

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This proposal seeks funding for my research program applying indirect methods to experimental nuclear astrophysics. The focus of this research is the experimental determination of the rates of nuclear reactions that occur in stars and astrophysical explosions. These reaction rates must be known in order to understand how energy is released in stars and stellar explosions, and to discover the origins of the chemical elements. Many of the most important reactions involve radioactive nuclei that don't occur naturally on Earth, and therefore must be created in the laboratory in order to be studied. Nuclear reaction rates can be determined directly if a beam of sufficient intensity can be produced, but such intense beams are available for only a tiny fraction of the relevant nuclei. In cases where direct study is presently impossible, indirect methods can be brought to bear. These methods, which involve the determination of the properties of the states of the compound nuclei formed in reactions of astrophysical interest, are quite powerful and often yield sufficient information to determine the nuclear reaction rates needed.