Experimental measurement of Zr91 ( n,γ)Zr92 at the CSNS Back-n …

Zr isotopes are important nuclides on the $s$-process path, and their neutron capture cross sections are of great significance for studying the evolution of heavy nuclei in the universe. In this work, the cross section of the $^{91}\mathrm{Zr}(n,\ensuremath{\gamma})^{92}\mathrm{Zr}$ reaction was measured at the China Spallation Neutron Source (CSNS) Back-n platform from 0.82 keV to 229 keV, essentially covering the energy range of astrophysical interest. In the experiment, a high-purity germanium detector with excellent energy resolution was used, which allowed for the accurate identification of characteristic $\ensuremath{\gamma}$ rays emitted during $^{92}\mathrm{Zr}$'s de-excitation, thereby enabling precise measurement of the neutron capture cross section. Furthermore, the measurement yielded the Maxwellian-averaged cross section of $56.4\ifmmode\pm\else\textpm\fi{}5.0$ mb calculated at $kT=30$ keV.