Towards an experimental constraint for the $ ^{56} $Ni(n,p)$ ^{56} $Co reaction rate which is key for the astrophysical $\nu p$~process.

Neutrino-driven winds in core-collapse supernovae, are an important site for the production of elements heavier than iron. If the neutrino-driven wind is slightly proton-rich as predicted by modern hydrodynamics simulations, then some of the elements heavier than Fe could be synthesized by the $ \nu $p-process making it a reasonable candidate for the Lighter Element Primary Process (LEPP), and a possible contributor to the abundances of light p-nuclei. The key $ ^{56} $Ni(n,p)$ ^{56} $ Co reaction rate for the neutrino-p process will be constrained experimentally through the $ ^{56} $Co(p,n)$ ^{56} $Ni cross section measurement in ReA3. This new experimental technique that enables the measurement of (p,n) reactions at low energies with radioactive beams and the corresponding proof-of-principle experiment using the $ ^{85} $Rb(p,n) reaction will be discussed.