Nuclear evolution in the Sun and in first generation stars
1.     First generation stars fuse 1H into heavier nuclides.
2.     At the end of their life, material in the core may be compressed
into a neutron star (NS). Our Sun, a second generation star, formed on this
product [Science 195, 208-209 (1977)].
3.     The NS acts as a giant nucleus, decaying with the emission
of neutrons (Q = 10-22 Mev/neutron; t1/2 approximatly equals to
1010 years) [Abstract 1041, Lunar Planetary Science Conference
XXXII, LPI Contribution No. 1080, ISSN No. 0161-5297, (2001)].
4.     After 1n -> 1H decay, the 1H-atoms migrate upward, carrying lighter elements and lighter isotopes
of each element to the solar surface [Meteoritics 18, 209-222 (1983)].
5.     En route most of the 1H-atoms are consumed by fusion. The small fraction that reach
the surface generate a solar wind flux of 3 x 1043 1H-atoms per year.
The above scenario
is consistent with isotopic ratios in the solar wind (SW) and with the observed fluxes of solar
neutrinos and SW-protons