Isomeric pair ${}^{95\mathrm{m},\mathrm{g}}\mathrm{Nb}$ in photonuclear reactions on ${}^{\mathrm{nat}}$Mo at end-point bremsstrahlung energy of 35-95 MeV

Abstract

The ${}^{\mathrm{nat}}\mathrm{Mo}(\gamma ,x\mathrm{np}{)}^{95\mathrm{m},\mathrm{g}}$Nb photonuclear reaction was studied using the electron beam from the NSC KIPT linear accelerator LUE-40. Experiment was performed using the activation and off-line $\gamma$-ray spectrometric technique. The experimental isomeric yield ratio $d(E_{\gamma \max })=Y_{\mathrm{m}}(E_{\gamma \max })/Y_{\mathrm{g}}(E_{\gamma \max })$ was determined for the reaction products ${}^{95\mathrm{m},\mathrm{g}}\mathrm{Nb}$ at the end-point bremsstrahlung energy $E_{\gamma \max }$ range of 35-95 MeV. The obtained values of $d(E_{\gamma \max })$ are in satisfactory agreement with the results of other authors and extend the range of previously known data. The theoretical values of the yields $Y_{\mathrm{m},\mathrm{g}}(E_{\gamma \max })$ and the isomeric yield ratio $d(E_{\gamma \max })$ for the isomeric pair ${}^{95\mathrm{m},\mathrm{g}}\mathrm{Nb}$ from the ${}^{\mathrm{nat}}\mathrm{Mo}(\gamma ,x\mathrm{np})$ reaction were calculated using the partial cross-sections $\sigma (E)$ from the TALYS1.95 code for six different level density models $LD$. The comparison showed a noticeable excess (more than 3.85 times) of the experimental isomeric yield ratio over all theoretical estimates. At the investigated range of $E_{\gamma \max }$ the theoretical dependence of $d(E_{\gamma \max })$ on energy was confirmed - the isomeric yield ratio smoothly decreases with increasing energy.

9 pages, 9 figures, 1 table

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