58​Ni(3​​He,t)5​8​Cu*(γ) Measurements with GODDESS to Constrain Astrophysical Rate of 5​7​Ni(p,γ)5​8​Cu*

Models of nucleosynthesis in supernovae can be validated by comparing the predicted abundance of specific radioisotopes with that inferred from the observation of gamma-rays emitted in supernovae remnants. The predicted abundance of one such isotope, 44Ti, is especially sensitive to the reaction rate of 57Ni(p,γ)58Cu.  Thus, in order to effectively validate these models, it is crucial to precisely determine the rate of 57Ni(p,γ)58Cu. Despite its importance, no experimental rate exists for this reaction, and theoretical rates differ by up to a factor of five in the temperature region of interest.  To experimentally constrain this rate, structure properties of 58Cu were measured via the 58Ni(3He,t)58Cu*(γ) reaction using GODDESS (GRETINA ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory’s ATLAS facility.  The coupling of these two highly efficient arrays allows for precise determination of 58Cu level energies via the detection of gamma-rays in coincidence with charged particles.  Because the reaction rate depends exponentially on these level energies, this precision is critical. Experimental data and preliminary results will be presented.

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