Measurement of the ¹⁸O(⍺,n)²¹Ne Reaction Cross Section for Applications of Nuclear Science

Understanding the decay product spectra is crucial for passive interrogation of nuclear material. For low burnup fuels, (⍺,n) reactions on ^17,18O have been identified as a dominant source of neutrons. In the energy range of the ⍺-decay of actinide elements, little data are available for the ¹⁸O(⍺,n)²¹Ne reaction, and it has been highlighted as a focus for experimental efforts. There is also interest in this reaction for several other applications for nuclear physics. For example, in isotope geochemistry, the production of ²¹Ne in Earth’s mantle gives unique insight into mantle processes. Existing data for this reaction are limited, with no partial cross section or neutron angular distribution data available. Therefore, a high-resolution measurement of the ¹⁸O(⍺,n)²¹Ne reaction was performed at the University of Notre Dame over the range E_⍺ = 2-8 MeV, to extract partial and total cross sections. 10 ODeSA detectors were used for neutron spectroscopy, analyzed via the spectrum unfolding technique. In addition, 2 LANL GEANIE HPGe detectors were used to detect secondary γ rays. Partial differential cross sections for gamma and neutron channels will be presented. SCALE neutron source calculations using these data will also be presented.