Delano and Cameron 1971
Delano, M.D., and A.G.W. Cameron, 1971: Nucleosynthesis in neutron rich supernova ejecta. Astrophys. Space Sci., 10, 203-226, doi:10.1007/BF00704083.
A nuclear reaction network of 903 different, strong and electromagnetic reactions, linking 107 chemical constituents is used to study the elements synthesized in the neutron rich material, ejected in supernova explosions. A large number of three body reactions virtually eliminates the usual bottle neck at the A=5 mass gap.
For initially high temperatures and densities, T = 1010K and ρ = 7×108 gm/cm3, with expansion time scales of 10-3-10-2 sec, three differentn top ratios, n/p = 4, n/p = 3/2, and n/p ~ 1, are considered for the ejected matter. In all three cases, the material synthesized is preponderantly heavy. For the n/p = 4 model, the conditions at the charged particle freeze-out are ideal for the "r-process". The onset of this rapid neutron capture phase is explicitly shown with a sequence of time lapse abundance plots.