Heavy element nucleosynthesis

A review is made of current nuclear astrophysical theory regarding the origin of the elements heavier than iron. The pre-supernova evolution of stars is very briefly described, and speculation is given regarding the supernova mechanism. In particular, the possible role of weak neutral currents is presented. The synthesis of the trans-iron nuclei via the s and r-processes is examined. Special emphasis is given to the r-process because it depends completely on the properties of nuclei off the valley of stability. Recent explosive r-process calculations are discussed, as well as plausible astrophysical sites. The alternative n-process is also described. The possible production by the r and/or n-processes of the almost mythical superheavy elements is reviewed. The sensitivity of the results to certain crudely estimated parameters is explicitly shown. Throughout the discussion, the importance of certain nuclear physics experiments and formalism is demonstrated. Areas where advances in nuclear physics will have a direct effect on the astrophysical results are cited. (64 refs).