Production of ${}^{180\mathrm{m}}$Hf in photoproton reaction ${}^{181}$Ta$(\gamma ,p)$ at energy $E_{\gamma \max }$ = 35-95 MeV

Abstract

The production of the ${}^{180\mathrm{m}}\mathrm{Hf}$ nuclei in the photoproton reaction ${}^{181}\mathrm{Ta}(\gamma ,p)$ was studied at end-point bremsstrahlung energies $E_{\gamma \max }$ = 35-95 MeV. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT with the use of the $\gamma$ activation and off-line $\gamma$-ray spectroscopy. The experimental values of the bremsstrahlung flux-averaged cross-sections $⟨\sigma (E_{\gamma \max }){⟩}_{\mathrm{m}}$ for the ${}^{181}\mathrm{Ta}(\gamma ,p{)}^{180\mathrm{m}}\mathrm{Hf}$ reaction were determined, and at $E_{\gamma \max }>55$ MeV obtained for the first time. The measured values, also as the literature data, are significantly exceed the theoretical flux-averaged cross-sections $⟨\sigma (E_{\gamma \max }){⟩}_{\mathrm{th}}$. The $⟨\sigma (E_{\gamma \max }){⟩}_{\mathrm{th}}$ values were calculated using the cross-section $\sigma (E)$ computed with the TALYS1.95 code for six different level density models. A comparative analysis of the calculated total cross-sections for the reactions ${}^{181}\mathrm{Ta}(\gamma ,p{)}^{180}\mathrm{Hf}$ and ${}^{181}\mathrm{Ta}(\gamma ,n{)}^{180}\mathrm{Ta}$ was performed. It was shown that the photoproton $(\gamma ,p)$ to photoneutron $(\gamma ,n)$ strength ratio is consistent with the estimates based on the isospin selection rules and the value from the $(e,e^{\prime }p)$ experiment.

9 pages, 4 figures, 2 tables

Cited by in corpus (1)

• Cross-section of the ${}^{95}\mathrm{Nb}$ production on natural molybdenum at the bremsstrahlung end-point energy up to 95 MeV