In the realm of energy research, understanding the fundamental processes that drive stellar nucleosynthesis is crucial for advancing our knowledge of energy production in stars, which can inform nuclear energy applications on Earth. Researchers V. I. Zhaba, Yu. A. Lashko, and V. S. Vasilevsky from the Bogolyubov Institute for Theoretical Physics in Ukraine have delved into the low-energy astrophysical S factors for reactions involving the beryllium-8 (8Be) compound system. Their work, published in the journal Physical Review C, offers insights that could have implications for both astrophysics and nuclear energy research.
The team investigated several nuclear reactions that occur at low energies and are relevant to primordial and stellar nucleosynthesis. These reactions involve different combinations of protons, neutrons, deuterons, lithium isotopes, beryllium isotopes, and helium-4. By using a microscopic many-channel three-cluster framework, the researchers calculated the astrophysical S factors, which are a measure of the reaction rates at stellar energies, for these reactions.
The study found that the calculated S factors for the reactions involving lithium-7 (7Li) and beryllium-7 (7Be) with protons and neutrons closely matched the experimental data, both in terms of absolute values and low-energy trends. This agreement suggests that the theoretical model used is robust and accurate for these specific reactions. However, for the reactions involving deuterons and lithium-6 (6Li), the calculated S factors were lower than expected at low energies. This discrepancy is attributed to the shifted threshold for the 6Li + d reaction and the absence of a broad subthreshold 2+ structure in the current model.
The researchers also performed a partial-wave analysis to identify the dominant contributions in each reaction channel and related them to specific 8Be resonances. This analysis demonstrated the importance of cluster polarization, a phenomenon previously shown to be crucial for the 8Be spectrum, in normalizing and determining the energy dependence of several S factors.
From a practical standpoint, understanding these nuclear reactions can help in the development of nuclear energy technologies. For instance, the production and destruction of lithium isotopes (7Li and 7Be) play a role in certain nuclear processes that could be harnessed for energy production. By quantifying the relative importance of neutron- and deuteron-induced processes, this research provides a hierarchy of reaction channels that could guide future energy research and development.
In conclusion, the work of Zhaba, Lashko, and Vasilevsky offers valuable insights into the fundamental processes driving stellar nucleosynthesis, with potential applications in the energy sector. Their findings contribute to our understanding of nuclear reactions and could inform the development of advanced nuclear energy technologies.
This article is based on research available at arXiv.