Intense fluxes of neutrinos are emitted by the hot neutron star produced in a supernova. The average supernova neutrino energies satisfy a robust hierarchy.(Eνe) < (Eνe) < (Eνμ(τ)) ≈ (Eνμ(τ)). The ve and v̄e capture rections on neutrons and protons, respectively, provide heating to drive a wind from the hot neutron star. The same reactions also determine the neutron-richness of the wind material. Nucleosynthesis via rapid neutron capture, the r-process, may occur in the wind material as it expands away from the neutron star. The neutron-richness of the wind material, and hence, the r-process nucleosynthesis therein, are sensitive to mixing between νμ(τ)/ν̄μ(τ) and νe/ν̄e (or sterile neutrinos νs/ν̄s) at the level of sin2 2θ ≲ 10-4 for δm2 ≳ 1 eV2. Indirect arguments and direct tests for the supernova origin of the r-process elements are discussed with a goal to establish supernova r-process nucleosynthesis as an important probe for neutrino mixing.
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This work was supportedi n part by the Departmenot f Energy under grant DE-FG02-87ER40328.