r-process event rate needed to reproduce the MW r-process mass. This includes material in both the stars and gas (interstellar and circumgalactic media). The right axis shows the results of our calculations for three different combinations of solar isotopes/metallicities (E. Anders & N. Grevesse 1989; K. Lodders et al. 2025) and r/s splits (M. Arnould et al. 2007; S. Bisterzo et al. 2014). The models agree very well for the heavier r-process elements with Z ≥ 56. The left axis converts this total r-process mass into an implied volumetric rate assuming 0.01M_⊙ of heavy r-process material is synthesized in each event and C_SFH = 1.