Nuclear structure of ${}^{243}\mathrm{Fm}$, ${}^{245}\mathrm{Fm}$, and their daughter nuclei were investigated via detection of their radioactive decays, $\alpha$, $\gamma$, and spontaneous fission. Measured $\alpha$-decay energies, half-lives, and branching ratios improve the literature data significantly. A signature for detection of the hitherto unknown ${}^{235}\mathrm{Cm}$ was found in the $\alpha$-decay chains from ${}^{243}\mathrm{Fm}$. Two groups of $\alpha$ events with average energies of 6.69(2) MeV and 7.01(2) MeV and with a half-life of $T_{1/2}={300}_{-100}^{+250}$ s are suggested to originate from ${}^{235}\mathrm{Cm}$. Tentative decay schemes for ${}^{243}\mathrm{Fm}$, ${}^{239}\mathrm{Cf}$, ${}^{235}\mathrm{Cm}$, and ${}^{245}\mathrm{Fm}$, ${}^{241}\mathrm{Cf}$ isotopes are suggested based on the present experimental data. Systematical trends of single-particle states in $N=141$ isotones of $Z=92–98$ nuclei are discussed.

• Received 26 February 2020
• Revised 29 July 2020
• Accepted 22 September 2020

DOI:https://doi.org/10.1103/PhysRevC.102.044312