The projectile-target system ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$${+}^{58}$Ni has been used to produce the neutron deficient N=49 isotones ${}_{}{}^{92}{}_{}{}^{}\mathrm{Tc}$, ${}_{}{}^{93}{}_{}{}^{}\mathrm{Ru}$, ${}_{}{}^{94}{}_{}{}^{}\mathrm{Rh}$, and ${}_{}{}^{95}{}_{}{}^{}\mathrm{Pd}$. The multidetector array NORDBALL including particle selection was used. The yrast level scheme could in three cases be determined up to and above spin values corresponding to the highest angular momenta attainable in the previously used configuration spaces for shell model calculations. The yrast level schemes of the N=49 isotones bear a striking relationship to those of the corresponding N=50 isotones. By interpreting the experimental high spin yrast structure in shell model configurations we hope to facilitate the choice of a restricted configuration space to be used for calculations. Generally, there is an intrinsic simplicity in most of the observed yrast or near-yrast states.

• Received 9 June 1993

DOI:https://doi.org/10.1103/PhysRevC.49.51