Photo-neutron reaction cross-sections for ^natMo in the bremsstrahlung end-point energies of 12-16 and 45-70 MeV

Abstract.

The ^natMo($\gamma$,xn)^{90, 91, 99}Mo reaction cross-sections were experimentally determined for the bremsstrahlung end-point energies of 12, 14, 16, 45, 50, 55, 60 and 70MeV by activation and off-line $\gamma$ -ray spectrometric technique and using the 20MeV electron linac (ELBE) at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany, and the 100MeV electron linac at the Pohang Accelerator Laboratory (PAL), Pohang, Korea. The ^natMo($\gamma$,xn)^{88, 89, 90, 91, 99}Mo reaction cross-sections as a function of photon energy were also calculated using the computer code TALYS 1.6. The flux-weighted average cross-sections were obtained from the literature data and the calculated values of TALYS based on mono-energetic photons and are found to be in general agreement with the present results. The flux-weighted average experimental and theoretical cross-sections for the ^natMo($\gamma$,xn)^{88, 89, 90, 91, 99}Mo reactions increase with the bremsstrahlung end-point energy, which indicates the role of excitation energy. After a certain energy, the individual ^natMo($\gamma$,xn) reaction cross-sections decrease with the increase of bremsstrahlung energy due to opening of other reactions, which indicates sharing of energy in different reaction channels. The ¹⁰⁰Mo($\gamma$, n) reaction cross-section is important for the production of ⁹⁹Mo , which is a probable alternative to the ⁹⁸Mo(n,$\gamma$) and ²³⁵U(n, f ) reactions.