Precision measurements of {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He total cross sections at Big Bang nucleosynthesis energies

Journal Article · Sat Apr 15 00:00:00 EDT 2006 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.73.045801· OSTI ID:20771495

Leonard, D S; Karwowski, H J; Brune, C R; Fisher, B M; Ludwig, E J ^[1]

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1. Department of Physics and Astronomy, University of North Carolina at Chapel Hill (United States) and Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States)

Recent Wilkinson Microwave Anisotropy Probe (WMAP) measurements have determined the baryon density of the Universe {omega}{sub b} with a precision of about 4%. With {omega}{sub b} tightly constrained, comparisons of Big Bang nucleosynthesis (BBN) abundance predictions to primordial abundance observations can be made and used to test BBN models and/or to further constrain abundances of isotopes with weak observational limits. To push the limits and improve constraints on BBN models, uncertainties in key nuclear reaction rates must be minimized. To this end, we made new precise measurements of the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He total cross sections at lab energies from 110 to 650 keV. A complete fit was performed in energy and angle to both angular distribution and normalization data for both reactions simultaneously. By including parameters for experimental variables in the fit, error correlations between detectors, reactions, and reaction energies were accurately tabulated by computational methods. With uncertainties around 2%{+-}1% scale error, these new measurements significantly improve on the existing data set. At relevant temperatures, by using the data of the present work, both reaction rates are found to be about 7% higher than those in the widely used NACRE (nuclear astrophysics compilation of reaction rates) database. These data will thus lead not only to reduced uncertainties, but also to modifications in the BBN abundance predictions.

• OSTI ID: 20771495
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 73, Issue 4; Other Information: DOI: 10.1103/PhysRevC.73.045801; (c) 2006 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
ANGULAR DISTRIBUTION
ANISOTROPY
ASTROPHYSICS
BARYONS
COMPARATIVE EVALUATIONS
CORRELATIONS
DENSITY
DEUTERIUM
DEUTERIUM TARGET
DEUTERON REACTIONS
ELEMENT ABUNDANCE
HELIUM 3
KEV RANGE
MICROWAVE RADIATION
NUCLEAR REACTION KINETICS
NUCLEOSYNTHESIS
TOTAL CROSS SECTIONS
TRITIUM
UNIVERSE