Spectra of two-step $\gamma$ cascades following neutron capture in ${}^{155,157}\mathrm{Gd}$ are measured using the two-Ge-detector facility installed at the thermal neutron beam of the research reactor LVR-15 at Řež. The main objective of this experiment is to obtain new information on photon strength functions, with the emphasis on the role of $M1$ scissors-mode vibration. An analysis of accumulated $\gamma$-ray spectra, made within the statistical model, leads to the conclusion that the scissors mode significantly affects $\gamma$ decay of all states of studied nuclei. Experimental data are compared to photon strength functions deduced from other experiments. Agreement of our results with those obtained from DANCE measurement of $\gamma$ spectra following resonance neutron capture is obtained.

• Received 14 September 2015

DOI:https://doi.org/10.1103/PhysRevC.92.064321