  The astrophysical environments capable of triggering heavy-element synthesis
via rapid neutron capture (the r-process) remain uncertain. While binary
neutron star mergers (NSMs) are known to forge r-process elements, certain rare
supernovae (SNe) have been theorized to supplement, or even dominate,
r-production by NSMs. However, the most direct evidence for such SNe, unusual
reddening of the emission caused by the high opacities of r-process elements,
has not been observed. Recent work identified the distribution of r-process
material within the SN ejecta as a key predictor of the ease with which signals
associated with r-process enrichment could be discerned. Though this
distribution results from hydrodynamic processes at play during the SN
explosion, thus far it has been treated only in a parameterized way. We use
hydrodynamic simulations to model how disk winds, the alleged locus of
r-production in rare SNe, mix with initially r-process-free ejecta. We study
mixing as a function of the wind mass and duration and of the initial SN
explosion energy, and find that it increases with the first two of these and
decreases with the third. This suggests that SNe accompanying the longest
long-duration gamma-ray bursts are promising places to search for signs of
r-process enrichment. We use semianalytic radiation transport to connect
hydrodynamics to electromagnetic observables, allowing us to assess the mixing
level at which the presence of r-process material can be diagnosed from SN
light curves. Analytic arguments constructed atop this foundation imply that a
wind-driven r-process-enriched SN model is unlikely to explain standard
energetic SNe.
