Proton-induced fission of ${}^{238}\mathrm{U}$ was used to produce neutron-rich ${}^{117}\mathrm{Rh}$ nuclei. After separation with the IGISOL mass separator coupled to the JYFLTRAP Penning trap, the monoisotopic ${}^{117}\mathrm{Rh}$ samples were delivered to a $\beta \gamma$ coincidence spectroscopy setup, in which the $\beta$ decay of its daughter, ${}^{117}\mathrm{Pd}$ was used to investigate the levels in ${}^{117}\mathrm{Ag}$. In another experiment, the excited ${}^{117}\mathrm{Ag}$ nuclei were produced in spontaneous fission of ${}^{252}\mathrm{Cf}$ and their $\gamma$-ray emission was studied with the Gammasphere array of Compton-suppressed Ge detectors. The complementary prompt-$\gamma$ and $\beta$-decay data revealed new levels and transitions in the neutron-rich ${}^{117}\mathrm{Ag}$ nucleus. A weakly deformed band on top of the $1/2^{-}$ ground state in ${}^{117}\mathrm{Ag}$ is observed for the first time, pointing to shape coexistence of the prolate and triaxial structures in this nucleus. The newly-observed $\gamma$-ray cascades allowed for the first time to determine the positions of the $1/2^{-}$ and $7/2^{+}\beta$-decaying isomers in ${}^{117}\mathrm{Ag}$ by $\gamma$ spectroscopy methods. Our measurements clearly indicate spin $1/2^{-}$ for the ground state in ${}^{117}\mathrm{Ag}$. The internal conversion coefficients were estimated experimentally for the low-energy transitions in ${}^{117}\mathrm{Ag}$, resulting in spin-parity assignment of $9/2^{+}$ for the 175.8-keV level in ${}^{117}\mathrm{Ag}$.

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• Beta decay
• Electromagnetic transitions
• Fission
• Isomer decays
• Nuclear structure & decays
• Rare & new isotopes
• 90 ≤ A ≤ 149