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The Astrophysical Journal


The American Astronomical Society


We demonstrate that a Population I concentration of primordial heavy seed nuclei, when present in the carbon- and oxygewrich core of the presupernova star and exposed to the temperature and free nucleon densities of explosive carbon burning, is efficiently transmuted into the rare species 365, 40K, 43Ar, 43Ca, 46Ca, 48Ca, 405c, 45Ti, 0Ti, 50V, 62Ni, 64Ni, 68Zn, 70Zn, and 76Ge in approximately their solar-system abundance ratios. If the temperature is high enough (T0 2.1) that at least 10 percent of the Fe and Ni seed nuclei undergo (p, ) reactions during the explosion, the nuclei 60Cu, 63Zn, 71Ga, 73Ce, and perhaps 75As can also be synthesized. These nuclei comprise virtually all of the relatively rare neutron-rich nuclei in the range 36 < A < 76 except 04Cr and 50Fe. We emphasize the dependence of the results upon the rates of important nuclear reactions, most of which are unknown. The temperature, density, and timescale of the carbon explosion all have a strong influence on the results as well. We therefore regard this paper as an exploratory survey of a very difficult problem that will give increasing information about nucleosynthesis as nuclear facts and models of nuclear explosions become more secure.