Thermonuclear fusion rates for tritium + deuterium using Bayesian methods
- Univ. of North Carolina, Chapel Hill, NC (United States)
- Univ. Paris-Saclay, Orsay Campus (France)
- Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Laboratory (TUNL), Durham, NC (United State)
The 3H(d, n) 4He reaction has a large low-energy cross section and will likely be utilized in future commercial fusion reactors. This reaction also takes place during Big Bang nucleosynthesis. Studies of both scenarios require accurate and precise fusion rates. To this end, we implement a one-level, two-channel R-matrix approximation into a Bayesian model. Our main goals are to predict reliable astrophysical S-factors and to estimate R-matrix parameters using the Bayesian approach. All relevant parameters are sampled in our study, including the channel radii, boundary condition parameters, and data set normalization factors. In addition, we take uncertainties in both measured bombarding energies and S-factors rigorously into account. Thermonuclear rates and reactivities of the 3H(d, n) 4He reaction are derived by numerically integrating the Bayesian S-factor samples. The present reaction rate uncertainties at temperatures between 1.0 MK and 1.0 GK are in the range of 0.2% to 0.6%. Our reaction rates differ from previous results by 2.9% near 1.0 GK.Our reactivities are smaller than previous results, with a maximum deviation of 2.9% near a thermal energy of 4 keV. The present rate or reactivity uncertainties are more reliable compared to previous studies that did not include the channel radii, boundary condition parameters, and data set normalization factors in the fitting. Finally, we investigate previous claims of electron screening effects in the published 3H(d, n) 4He data. No such effects are evident and only an upper limit for the electron screening potential can be obtained.
- Research Organization:
- Duke Univ., Durham, NC (United States); University of North Carolina, Chapel Hill, NC (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP); National Aeronautics and Space Administration (NASA)
- Grant/Contract Number:
- FG02-97ER41033; FG02-97ER41041; 14-ATP14-0007
- OSTI ID:
- 1610381
- Alternate ID(s):
- OSTI ID: 1491608; OSTI ID: 1658835
- Journal Information:
- Physical Review C, Vol. 99, Issue 1; ISSN 2469-9985
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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