Cosmological cosmic rays and the 6Li plateau

Production of 6Li by a — a fusion in the ISM is a primary process, so that its interstellar abundance at low metallicities would be expected to track primary elements 

Alternatively, 6Li in low-metallicity stars could be the result ol 4Hc(3Hc, p) reactions in stellar flares, analogous to effects found in some energetic solar flares (Tatischeff Thibaud 2007). In this case there is expected to be real scatter in the 6Li plateau, due to variations in (present or past) stellar rotation speed. 

Beryllium was first demonstrated to be present in low-metallicity stars by Gilmore, Edvardsson and Nissen (1991) and soon confirmed by others, e.g. Ryan ei al. (1992) who gave the argument for a flattening in the Be/Fe ratio at [Fe/H] 

The discussion of the GCE of light elements formed by cosmic-ray spallation is based on Pagel (1994) and has a somewhat different outlook from many other treatments in the literature, e.g. Fields, Olive and Schramm (1995), which should be consulted to get another viewpoint. A numerical treatment of the Simple model by Vangioni-Flam et al. (1990) gave similar results to the ones derived more simply here, as did the discussion of inflow models by Prantzos (1994). 

The relation between 6Li abundances and the (uncertain) cosmic y-ray background has been discussed by Fields and F rodanovic (2005) as pointed out by Rollinde et al. (2005), there is no inconsistency with the plateau. 

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