2022ApJ...927..116J

The weak r-process offers an explanation of the formation of lighter heavy elements 36 <= Z <= 47 in ultra-metal-poor stars. Magnetohydrodynamically driven supernovae are thought to be a robust astronomical site of the weak r-process and recently gave a good description of the observational abundance pattern of an extremely metal-poor star. However, the characteristics of nuclear reactions in the MHD nucleosynthesis are not as clear as in another site, that of core-collapse supernovae. In this paper, the trajectories of the MHD model are implemented into SkyNet network calculations. By varying the reaction rates of each type, the (α,n) reactions are much more active than other types of reactions, such as (n,γ), (p,γ), (n,p), and (α,p). A further detailed sensitivity study investigates the (α,n) reactions and lists the most influential ones over the whole range, and the impactful reactions on each element from Sr to Ag are tabulated.