Nuclear fusion in dense matter: Reaction rate and carbon burning

Journal Article · Mon Aug 01 00:00:00 EDT 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.72.025806· OSTI ID:20698938

Gasques, L R; Afanasjev, A V; Beard, M; Wiescher, M ^[1]; Aguilera, E F ^[2]; Chamon, L C ^[3]; Ring, P ^[4]; Yakovlev, D G ^[5]

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1. Department of Physics and Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
2. Departamento del Accelerador, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, C.P. 11801, Destrito Federal (Mexico)
3. Departamento de Fisica Nuclear, Instituto de Fisica da Universidade de Sao Paulo, Caixa Postal 66318, 05315-970, Sao Paulo, SP (Brazil)
4. Physik-Department, Technische Universitat Muenchen, D-85747, Garching (Germany)
5. Ioffe Physical Technical Institute, Poliekhnicheskaya 26, RU-194021 St. Petersburg (Russian Federation)

In this paper we analyze the nuclear fusion rates among equal nuclei for all five different nuclear burning regimes in dense matter (two thermonuclear regimes, two pycnonuclear ones, and the intermediate regime). The rate is determined by Coulomb barrier penetration in dense environments and by the astrophysical S factor at low energies. We evaluate previous studies of the Coulomb barrier problem and propose a simple phenomenological formula for the reaction rate that covers all cases. The parameters of this formula can be varied to take into account current theoretical uncertainties in the reaction rate. The results are illustrated for the example of the {sup 12}C+{sup 12}C fusion reaction. This reaction is important for the understanding of nuclear burning in evolved stars, in exploding white dwarfs producing type Ia supernovas, and in accreting neutron stars. The S factor at stellar energies depends on a reliable fit and extrapolation of the experimental data. We calculate the energy dependence of the S factor by using a recently developed parameter-free model for the nuclear interaction, taking into account the effects of the Pauli nonlocality. For illustration, we analyze the efficiency of carbon burning in a wide range of densities and temperatures of stellar matter with the emphasis on carbon ignition at densities {rho} > or approx. 10{sup 9} g cm{sup -3}.

• OSTI ID: 20698938
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 72, Issue 2; Other Information: DOI: 10.1103/PhysRevC.72.025806; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CARBON 12 REACTIONS
CARBON 12 TARGET
CARBON BURNING
COULOMB FIELD
EFFICIENCY
ENERGY DEPENDENCE
EXTRAPOLATION
HEAVY ION FUSION REACTIONS
NEUTRON STARS
NUCLEAR REACTION KINETICS
SUPERNOVAE
THERMONUCLEAR IGNITION
WHITE DWARF STARS