New measurements of (α,n) cross sections using deuterated liquid scintillator neutron detector spectrum unfolding

Kevin Macon

Postdoctoral Researcher

LSU Experimental Nuclear Physics

https://lsu.zoom.us/j/97150018953?pwd=aWtRT0FycVV1MWdUeU5oQmtVd3d4dz09

Meeting ID: 971 5001 8953

Passcode: 909663

Accurate cross section data on neutron producing reactions is important for understanding a wide range of problems in nuclear astrophysics and nuclear applications. Specifically (α,n) reactions on light, stable isotopes that can have a significant impact on neutron production and can be measured directly in the laboratory. Often, previous cross section measurements used moderated neutron counters which are insensitive to the detected neutron’s energy. This results in a significant amount of available data being limited to total cross sections summed over contributions from the resulting nucleus in the ground state or accessible excited states.

In contrast, neutron energy spectroscopy enables individual partial cross section measurements, discriminating backgrounds from contaminates, and improving corrections for energy dependent detection efficiencies. In this talk, I will describe the recently commissioned Oak Ridge Deuterated Spectroscopic Array (ODeSA) and the spectrum unfolding analysis technique developed to extract the neutron energy distributions. I will give an overview of recent (α, n) reaction measurements at the Notre Dame Nuclear Science Laboratory St. Ana 5U accelerator with an emphasis on results of new measurements on 17O and 25Mg important for nucleosynthesis in massive stars, and highlight a 13C measurement and its relevance for geoneutrinos.