The flux weighted cross sections of 179Hf(γ,γ')179mHf and natHf(γ,x)179mHf reactions at 8 MeV and 15 MeV bremsstrahlung end point energies

Highlights: • Flux weighted cross sections of ¹⁷⁹Hf(γ,γ')^179mHf at 8 MeV bremsstrahlung end point energies. • Flux weighted cross sections of ^natHf(γ,x)^179mHf at 15MeV bremsstrahlung end point energies. • Bremsstrahlung spectra simulated using Geant4. • Estimation of photon flux using ¹¹⁵In(γ,γ')^115mIn and ¹⁹⁷Au(γ,n)¹⁹⁶Au at 8 MeV and 15 MeV bremsstrahlung respectively. • Theoretical cross sections obtained form TENDL-2019 and TALYS 1.95. • Comparison of experimental data and theoretical calculations of cross-section with EXFOR data. For the hafnium element, the cross sections of ¹⁷⁹Hf(γ,γ′)^179mHf and ^natHf(γ,x)^179mHf reactions were measured at 8 MeV and 15 MeV bremsstrahlung end point energies respectively using activation method and off-line gamma-ray spectroscopy. The bremsstrahlung radiation spectra were generated by bombarding a 0.1 mm tungsten target with 8 MeV and 15 MeV electrons at 5 μA beam current and also theoretically simulated by GEANT4 computer code. The flux weighted average cross sections of ¹⁷⁹Hf (γ,γ′)^179mHf and ^natHf(γ,x)^179mHf reactions were measured by using ¹¹⁵In(γ,γ')^115mIn and ¹⁹⁷Au(γ,n)¹⁹⁶Au as flux monitor reactions at 8 MeV and 15 MeV bremsstrahlung radiation respectively. The measured cross sections are found close to the corresponding theoretical cross sections estimated by TALYS 1.95 and TENDL 2019 computer codes. These hafnium cross sections at 8 MeV and 15 MeV bremsstrahlung radiation will be new additions to the EXFOR library, as so far not reported in literature.