Experimental validation of ²³Na(, n)²²Na cross section

Photonuclear reactions are gaining importance due to their influence on the shielding and activation of components of widely spread accelerators. Therefore, there is a need for accurate data describing photonuclear reactions. The MT25 microtron operated at NPI was used for validation of cross section in the bremsstrahlung. The gold and copper activation foils with known cross sections were used as flux monitors. The bremsstrahlung spectra was simulated with Geant4 code and the spectral averaged cross section above 10 MeV for reaction Na-23(gamma, x)Na-22 was calculated. The experimental result was compared with data from the evaluated data libraries and EXFOR database. It was proved that the facility can be used for validation of cross sections and it was showed that all libraries overestimate the photon cross section on Na-23 with the best results with data from JENDL-5 library.