${}^{40}$Ar($n$,$p$)${}^{40}$Cl reaction cross section between 9 and 15 MeV

The activation technique was used to measure the cross section for the reaction ${}^{40}\mathrm{Ar}(n,p){}^{40}\mathrm{Cl}$ in 0.5 MeV energy steps in the neutron energy range between 9 and 15 MeV. These data are important for estimating background contributions in neutrinoless double-beta decay and dark matter searches, as well as in argon-based large neutrino detectors. The data are compared to evaluations and theoretical predictions.

Figure 1

Schematic of experimental setup consisting of deuterium gas cell (D${}_2$) for ${}^2\mathrm{H}(d,n){}^3\mathrm{He}$ reaction and high-pressure argon cell.

Figure 2

Partial gamma-ray spectrum of ${}^{40}\mathrm{Cl}$ obtained with the HPGe detector during (a) first minute, (b) second minute, and (c) fourth minute of counting after neutron activation of ${}^{40}\mathrm{Ar}$. The line of interest at 1461 keV is indicated.

Figure 3

Decay curve of 1461 keV yield from ${}^{40}\mathrm{Cl}$.

Figure 4

Results for ${}^{40}\mathrm{Ar}(n,p){}^{40}\mathrm{Cl}$ cross section obtained in the present work (triangle) in comparison to previous data (dot, diamond, and hexagon) and evaluations (solid and dashed curves) and a theoretical prediction (dotted curve).