Triple collisions e− p 7Be in solar plasma

Abstract

Several nuclear reactions involving the 7 Be nucleus, not included into the standard model of the pp-chain, are discussed. A qualitative analysis of their possible influence on the fate of the 7 Be in solar plasma and of their role in the interpretation of the solar neutrino experiments is given. As an example, the reaction rate of the nonradiative production of 8 B in the triple collision p + e − + 7 Be → 8 B+e − is estimated in the framework of the adiabatic approximation. For the solar interior conditions the triple collision reaction rate is approximately 10 −4 of that for the binary process p + 7 Be → 8 B + γ. [PACS numbers: 21.45.+v, 97.10.Cv]

Non-radiative synthesis of7Be in solar plasma

“…Calculations of the three-body reaction rates performed so far [3][4][5] corroborate this by showing that the simplified considerations based on the frequency of collisions overestimate the differences between the two-and three-body reaction rates. Thus, for example, in [3] it was shown that under the conditions which prevailed during the primordial nucleosynthesis, the non-radiative capture e + n + p → e + d occurs at a reaction rate which is five orders of magnitude less than the corresponding rate for the radiative capture n + p → γ + d. In [4,5] the reaction rates for the non-radiative processes e + p + d → e + 3 He and e + p + 7 Be → e + 8 B were calculated. Again, it was found that they are only four orders of magnitude less than for corresponding binary reactions p + d → γ + 3 He and p + 7 Be → γ + 8 B.…”

“…Calculations of the three-body reaction rates performed so far [3][4][5], corroborate this by showing that the simplified considerations based on the frequency of collisions overestimate the differences between the two-and three-body reaction rates. Thus, for example, in Ref.…”

“…[3] it was shown that under the conditions which prevailed during the primordial nucleosynthesis, the non-radiative capture e + n + p → e + d occurs at a reaction rate which is five orders of magnitude less than the corresponding rate for the radiative capture n+ p → γ + d. In Refs. [4,5] the reaction rates for the non-radiative processes e + p + d → e + 3 He and e + p + 7 Be → e + 8 B were calculated. Again, it was found that they are only four orders of magnitude less than for corresponding binary reactions p+d → γ + 3 He and p+ 7 Be → γ + 8 B.…”

Few nucleón dynamics in a nuclear medium

“…Recently, triple reactions, e.g. e + 3 He + α → 7 Be + e to be compared to 3 He + α → 7 Be + γ have been investigated and found to be rather small in plasmas at solar conditions [13]. However, note that triple collisions are mostly non-radiative and that they may be more important for other stars than the sun or at the early universe [13].…”