Effects of the Recombination of Nucleons into α-Particles on the R-process in Proto-magnetar Wind

We take the recombination of nucleons to α-particles into account in proto-magnetar winds and evaluate its effects on r-process nucleosynthesis. The proto-magnetar winds are described in the time-independent Newtonian magnetohydrodynamic wind scenario. It is found that stellar rotation and strong magnetic fields significantly affect the properties of the winds. Also, the fact that the recombination of nucleons can enhance the wind entropy by approximately twenty percent and somewhat reduce the expansion timescale indicates that the effects of this recombination on the r-process can not be ignored.