Cross-sections for the ${^{27}\!\rm{al}}(γ,\textit{x})^{22}\rm{na}$ multichannel reaction with the 28.3 mev difference of the reaction thresholds

Abstract

The bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and the cross-sections per equivalent photon $\langle{σ(E_{\rm{γmax}})_{\rm{Q}}}\rangle$ were first measured for the photonuclear multichannel reaction ${^{27}\!\rm{Al}}(γ,\textit{x})^{22}\rm{Na}$ at end-point bremsstrahlung gamma energies ranging from 35 MeV to 95 MeV. The experiments were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the $γ$-activation technique. The bremsstrahlung quantum flux was calculated with the program GEANT4.9.2 and, in addition, was monitored by means of the $^{100}\rm{Mo}(γ,n)^{99}\rm{Mo}$ reaction. The flux-averaged cross-sections were calculated using the partial cross-section $σ(E)$ values computed with the TALYS1.95 code for different level density models. Consideration is given to special features of calculating the cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and $\langle{σ(E_{\rm{γmax}})_{\rm{Q}}}\rangle$ for the case of the final nucleus $^{22}\rm{Na}$ production in the $^{27}\!\rm{Al}$ photodisintegration reaction via several partial channels $\textit{x}$: $\rm{n}α+ dt + npt + 2n{^{3}\rm{He}} + n2d + 2npd + 2p3n$.