Measurements of the ${}^{27}\mathrm{Al}(\alpha ,n)$ Thick Target Yield Near Threshold

Abstract

We present results from direct measurements of the ${}^{27}\mathrm{Al}(\alpha ,n)$ thick target yield from laboratory incident energies $E_{\alpha }\approx$ 3$-$5~MeV, performed with the ${}^3$HeBF${}_3$ Giant Barrel (HeBGB) neutron detector at the Edwards Accelerator Laboratory. Our measurements have a small energy cadence in order to address discrepancies and sparseness of thick-target yield data sets existing for this energy region. We find general agreement with existing data sets, including yields derived from cross section data, while resolving a discrepancy between existing thick-target yield data sets for $E_{\alpha }\approx 4-5$~MeV. However, for $E_{\alpha }<3.5$~MeV, our results are substantially lower than previous thick-target yield data and somewhat larger than yields calculated from existing cross section data. Our data complete the energy-range needed for estimates of the ${}^{27}\mathrm{Al}(\alpha ,n)$ contribution to neutrino and dark matter detector backgrounds and result in increased viability of ${}^{27}\mathrm{Al}(\alpha ,n)$ as a plasma diagnostic tool at fusion facilities such as the National Ignition Facility.

Accepted to Nuclear Science and Engineering

References in corpus (5)

• Evaluation of (alpha,n) Induced Neutrons as a Background for Dark Matter Experiments
• The Edwards Accelerator Laboratory at Ohio University
• Sensitivity of ${}^{44}$Ti and ${}^{56}$Ni production in CCSN shock-driven nucleosynthesis to reaction rates
• The ${}^3$He BF${}_3$ Giant Barrel (HeBGB) Neutron Detector
• First measurement of the ${}^{10}\mathrm{B}(\alpha ,n{)}^{13}\mathrm{N}$ reaction in an inertial confinement fusion implosion at the National Ignition Facility: Initial steps toward the development of a radiochemistry mix diagnostic

Cited by in corpus (1)

• Optimised neutron yield calculations from ($\alpha ,n$) reactions with the modified SOURCES4 code