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Particle decay branching ratios for states of astrophysical importance in 19Ne

D. W. Visser·J. A. Caggiano·R. Lewis·W. B. Handler·A. Parikh·P. D. Parker
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Abstract

We have measured proton and alpha-particle branching ratios of excited states in 19Ne formed using the 19F(3He,t) reaction at a beam energy of 25 MeV. These ratios have a large impact on the astrophysical reaction rates of 15O(alpha,gamma), 18F(p,gamma) and 18F(p,alpha), which are of interest in understanding energy generation in x-ray bursts and in interpreting anticipated gamma-ray observations of novae. We detect decay protons and alpha-particles using a silicon detector array in coincidence with tritons measured in the focal plane detector of our Enge split-pole spectrograph. The silicon array consists of five strip detectors of the type used in the Louvain-Edinburgh Detector Array, subtending angles from 130 degrees to 165 degrees with approximately 14% lab efficiency. The correlation angular distributions give additional confidence in some prior spin-parity assignments that were based on gamma branchings. We measure Gamma_p/Gamma=0.387+-0.016 for the 665 keV proton resonance, which agrees well with the direct measurement of Bardayan et al.

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D. W. Visser, J. A. Caggiano, R. Lewis, W. B. Handler, A. Parikh, P. D. Parker. 2004-02-26. Particle decay branching ratios for states of astrophysical importance in 19Ne. https://doi.org/10.1103/physrevc.69.048801

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