Photonuclear reactions cross-sections at energies up to 100 MeV for different experimental setups
In experiments on the electron linac LUE-40 of RDC "Accelerator" NSC KIPT, the flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{exp}}$ of photonuclear reactions ${^{100}\rm{Mo}}(γ,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(γ,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(γ,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(γ,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(γ,n)^{180g}\rm{Ta}$ were measured using the $γ$-activation technique. The theoretical flux-average cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ were computed using the partial cross-section $σ(E)$ values from the TALYS1.9-1.95 codes and bremsstrahlung $γ$-flux calculated using GEANT4.9.2. Two different experimental setups were used in the experiments: an aluminum electron absorber and a deflecting magnet to clean the bremsstrahlung $γ$-flux from electrons. A comparison of the flux-average cross-sections measured for two experimental setups was performed. The possibility of using the reactions ${^{100}\rm{Mo}}(γ,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(γ,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(γ,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(γ,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(γ,n)^{180g}\rm{Ta}$ as monitors of the bremsstrahlung $γ$-flux for the energy range 30-100 MeV was investigated.