Cross-sections for the 27Al(γ, x)22Na multichannel reaction with the 28.3 MeV difference of reaction thresholds

The bremsstrahlung flux-averaged cross-sections <sigma(E-gamma max)> and the cross-sections per equivalent photon <sigma(E-gamma max)(Q)> were first measured for the photonuclear multichannel reaction Al-27(gamma,x)Na-22 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 using the gamma-activation technique. The bremsstrahlung quantum flux was calculated with the GEANT4.9.2 program and was also monitored via the Mo-100(gamma, n)Mo-99 reaction. The flux-averaged cross-sections were calculated using the partial cross-section sigma(E) values computed with the TALYS1.95 code for different level density models. Consideration is given to special features of calculating the cross-sections <sigma(E-gamma max)> and <sigma(E-gamma max)(Q)> for the case of the final nucleus Na-22 via several partial channels x: n alpha + dt + npt + 2n(3)He + n2d + 2npd + 2p3n.