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S-Process Studies: Exact Evaluation Of An Exponential Distrubution Of Exposures, Donald D. Clayton, Richard A. Ward
S-Process Studies: Exact Evaluation Of An Exponential Distrubution Of Exposures, Donald D. Clayton, Richard A. Ward
Publications
We show that the solution of the s-process chain can be easily evaluated exactly if the seed nuclei have been irradiated with an exponential distribution of exposures. For the same distribution of exposures, the shape of the akNk curve past the last seed is independent of the distribution of seed nuclei. Evaluation of these results confirms the accuracy of the well-known CFHZ approximation.
On The E-Process: Its Components And Their Neutron Excesses, Kem L. Hainebach, Donald D. Clayton, W David Arnett, S E. Woosley
On The E-Process: Its Components And Their Neutron Excesses, Kem L. Hainebach, Donald D. Clayton, W David Arnett, S E. Woosley
Publications
The pattern of abundances within the iron-abundance peak of the solar system is analyzed for various Cr, Fe, and Ni abundances, and a method is developed for finding the best fit to a given set of abundances with a chosen number of zones, i.e., mass contributions characterized by differing values of eta. This material can be synthesized by a superposition of e-process compositions in a low-eta region (eta = 0.003) and a high-eta region (eta = 0.065 -0.080) with at least 85% coming from the low-eta region. Addition of a third eta zone is unproductive. The applicability of the particle-poor …
S-Process Studies: Exact Solution To A Chain Having Two Distinct Cross-Section Values, Donald D. Clayton, Michael J. Newman
S-Process Studies: Exact Solution To A Chain Having Two Distinct Cross-Section Values, Donald D. Clayton, Michael J. Newman
Publications
We present the exact solution to an s-process chain having two distinct values for the cross-sections. The comparison of this exact solution with the CFHZ approximate solution to the same problem reveals that approximate solution to be adequate for most astrophysical problems.
Nucelosynthesis In White-Dwarf Atmospheres, Fred Hoyle, Donald D. Clayton
Nucelosynthesis In White-Dwarf Atmospheres, Fred Hoyle, Donald D. Clayton
Publications
Consideration of events by which both s- and r-process nucleosynthesis may occur on the surfaces of white-dwarf stars. The main requirement is that the accreted hydrogen be mixed with comparable numbers of C-12 (or other alpha nuclei) before a runaway capture of protons takes place. Subsequent events offer many possibilities for nucleosynthesis and stars of peculiar composition. A new mechanism for a surface s-process due to few-MeV protons is also described. Concluding comments concern cosmic gamma-ray bursts and the origin of anomalous low-energy galactic cosmic rays.