Analysis of suprathermal nuclear processes in the solar core plasma

作者：Voronchev Victor T; Nakao Yasuyuki; Watanabe Yukinobu

来源：Journal of Physics G: Nuclear and Particle Physics , 2017, 44(4): 045202.

DOI：10.1088/1361-6471/aa5f30

• fast alpha-particles
• suprathermal reactions
• solar core plasma
• CNO cycle

A consistent model for the description of suprathermal processes in the solar core plasma naturally triggered by fast particles generated in exoergic nuclear reactions is formulated. This model, based on the formalism of in-flight reaction probability, operates with different methods of treating particle slowdown in the plasma, and allows for the influence of electron degeneracy and electron screening on processes in the matter. The model is applied to examine slowing-down of 8.7 MeV alpha-particles produced in the Li-7(p, alpha) a reaction of the pp chain, and to analyze suprathermal processes in the solar CNO cycle induced by them. Particular attention is paid to the suprathermal N-14(alpha, p) O-17 reaction unappreciated in standard solar model simulations. It is found that an appreciable non-standard (alpha, p) nuclear flow due to this reaction appears in the matter and modifies running of the CNO cycle in similar to 95% of the solar core region. In this region at R > 0.1R(circle dot), normal branching of nuclear flow N-14 <- O-17. (F-18). -> O-18 transforms to abnormal sequential flow N-14 -> O-17 -> (F-18) -> O-18, altering some element abundances. In particular, nuclear network calculations reveal that in the outer core the abundances of O-17 and O-18 isotopes can increase by a factor of 20 as compared with standard estimates. A conjecture is made that other CNO suprathermal (alpha, p) reactions may also affect abundances of CNO elements, including those generating solar neutrinos.

• 出版日期2017-4