Constraining the ³⁰P(p,γ)³¹S reaction using ³⁰P(d,pγ)³¹P with GODDESS

During classical nova nucleosynthesis, the ³⁰P(p,γ)³¹S reaction rate critically affects the mass flow into the A=30-40 range, impacting the abundances of isotopes of phosphorus, sulfur, and silicon. Direct measurement of the (p,γ) reaction is not currently possible due to insufficient beam intensities. The rate of this reaction depends on undetermined spectroscopic strengths of low-lying resonances in ³¹S, located between 6 and 7 MeV in excitation energy. Due to experimental challenges to measure the proton spectroscopic factors on unstable nuclei, we performed a ³⁰P(d,pγ)³¹P neutron transfer reaction measurement using the newly commissioned GODDESS (GRETINA-ORRUBA: Dual Detectors for Experimental Structure Studies) detection system­—with an 8 MeV/u ³⁰P beam, from RAISOR at ATLAS, in order to provide constraints on the spectroscopic strengths for ³¹S levels via mirror symmetry. Details of the experiment and progress in data analysis, including excitation energy spectrums, proton-gamma matrices, angular distributions, spectroscopic factors, and reaction rates, will be presented.