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Title: Elements just beyond iron: Formation during explosive carbon burning

Abstract

The synthesis of the elements just beyond iron during explosive carbon burning has been studied using an exact n (neutron)-process calculation incorporating neutron captures, charged particle reactions, and beta-decay in network covering the elements Cr--Zr. The temperature, density and free particle abundances were taken directly from explosive carbon-buring calculations. Heavy element seed distributions incorporating the s-process enhancements from core helium burning were employed, along with realistic postshock conditions, to obtain an evolution characteristic of the average massive star contributing material to the solar system. The results for the heavy isotopes are significantly different from earlier calculations. In particular, the r-process components of the species in the mass range A = 69--77 are coproduced (except for /sup 72/Ge), but not the nickel and copper isotopes. Only 0.04% of the matter in the Galaxy must be exposed to this type of nucleosynthesis to produce r-process components of the A = 69--77 isotopes, but this level underproduces the light products of explosive carbon burning, /sup 12/C--/sup 31/P, by a large amount. Therefore, explosive carbon burning may be the source of the neutron-rich isotopes beyond copper, but this process cannot simultaneously produce the light species whose synthesis is normally ascribed to explosive carbon burning.more » The n-process during explosive carbon burning may, however, contribute material to the ultraheavy (UH) cosmic rays or to isotopic anomalies in meteorites. The element zirconium, in particular, and possibly krypton offer tests for the presence of explosive carbon-burning--produced material.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Enrico Fermi Institute, University of Chicago
OSTI Identifier:
6218953
Resource Type:
Journal Article
Journal Name:
Astrophys. J., Suppl. Ser.; (United States)
Additional Journal Information:
Journal Volume: 45:4
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; NUCLEOSYNTHESIS; CARBON BURNING; NEUTRON REACTIONS; STARS; BARYON REACTIONS; HADRON REACTIONS; NUCLEAR REACTIONS; NUCLEON REACTIONS; STAR BURNING; 640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar, Radio & X-Ray Sources

Citation Formats

Wefel, J.P., Schramm, D.N., Blake, J.B., and Pridmore-Brown, D. Elements just beyond iron: Formation during explosive carbon burning. United States: N. p., 1981. Web. doi:10.1086/190726.
Wefel, J.P., Schramm, D.N., Blake, J.B., & Pridmore-Brown, D. Elements just beyond iron: Formation during explosive carbon burning. United States. doi:10.1086/190726.
Wefel, J.P., Schramm, D.N., Blake, J.B., and Pridmore-Brown, D. Wed . "Elements just beyond iron: Formation during explosive carbon burning". United States. doi:10.1086/190726.
@article{osti_6218953,
title = {Elements just beyond iron: Formation during explosive carbon burning},
author = {Wefel, J.P. and Schramm, D.N. and Blake, J.B. and Pridmore-Brown, D.},
abstractNote = {The synthesis of the elements just beyond iron during explosive carbon burning has been studied using an exact n (neutron)-process calculation incorporating neutron captures, charged particle reactions, and beta-decay in network covering the elements Cr--Zr. The temperature, density and free particle abundances were taken directly from explosive carbon-buring calculations. Heavy element seed distributions incorporating the s-process enhancements from core helium burning were employed, along with realistic postshock conditions, to obtain an evolution characteristic of the average massive star contributing material to the solar system. The results for the heavy isotopes are significantly different from earlier calculations. In particular, the r-process components of the species in the mass range A = 69--77 are coproduced (except for /sup 72/Ge), but not the nickel and copper isotopes. Only 0.04% of the matter in the Galaxy must be exposed to this type of nucleosynthesis to produce r-process components of the A = 69--77 isotopes, but this level underproduces the light products of explosive carbon burning, /sup 12/C--/sup 31/P, by a large amount. Therefore, explosive carbon burning may be the source of the neutron-rich isotopes beyond copper, but this process cannot simultaneously produce the light species whose synthesis is normally ascribed to explosive carbon burning. The n-process during explosive carbon burning may, however, contribute material to the ultraheavy (UH) cosmic rays or to isotopic anomalies in meteorites. The element zirconium, in particular, and possibly krypton offer tests for the presence of explosive carbon-burning--produced material.},
doi = {10.1086/190726},
journal = {Astrophys. J., Suppl. Ser.; (United States)},
number = ,
volume = 45:4,
place = {United States},
year = {1981},
month = {4}
}