IMPACT OF SUPERNOVA DYNAMICS ON THE {nu}p-PROCESS
- Department of Physics, University of Basel, CH-4056 Basel (Switzerland)
- Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States)
- Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany)
We study the impact of the late-time dynamical evolution of ejecta from core-collapse supernovae on {nu}p-process nucleosynthesis. Our results are based on hydrodynamical simulations of neutrino-driven wind ejecta. Motivated by recent two-dimensional wind simulations, we vary the dynamical evolution during the {nu}p-process and show that final abundances strongly depend on the temperature evolution. When the expansion is very fast, there is not enough time for antineutrino absorption on protons to produce enough neutrons to overcome the {beta}{sup +}-decay waiting points and no heavy elements beyond A = 64 are produced. The wind termination shock or reverse shock dramatically reduces the expansion speed of the ejecta. This extends the period during which matter remains at relatively high temperatures and is exposed to high neutrino fluxes, thus allowing for further (p, {gamma}) and (n, p) reactions to occur and to synthesize elements beyond iron. We find that the {nu}p-process starts to efficiently produce heavy elements only when the temperature drops below {approx}3 GK. At higher temperatures, due to the low alpha separation energy of {sup 60}Zn (S{sub {alpha}} = 2.7 MeV) the reaction {sup 59}Cu(p, {alpha}){sup 56}Ni is faster than the reaction {sup 59}Cu(p, {gamma}){sup 60}Zn. This results in the closed NiCu cycle that we identify and discuss here for the first time. We also investigate the late phase of the {nu}p-process when the temperatures become too low to maintain proton captures. Depending on the late neutron density, the evolution to stability is dominated by {beta}{sup +} decays or by (n, {gamma}) reactions. In the latter case, the matter flow can even reach the neutron-rich side of stability and the isotopic composition of a given element is then dominated by neutron-rich isotopes.
- OSTI ID:
- 22034624
- Journal Information:
- Astrophysical Journal, Vol. 750, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALPHA PARTICLES
ANTINEUTRINOS
ASTROPHYSICS
BINDING ENERGY
COMPUTERIZED SIMULATION
COPPER 59
ELEMENT ABUNDANCE
EVOLUTION
ISOTOPE RATIO
MEV RANGE
NEUTRINO REACTIONS
NEUTRINO-PROTON INTERACTIONS
NEUTRON DENSITY
NEUTRON REACTIONS
NICKEL 56
NUCLEAR DECAY
NUCLEOSYNTHESIS
PROTON REACTIONS
SUPERNOVAE
ZINC 60