Spectroscopic Study ofRh105by Direct (He3,d) and (p,α) Reactions

The level structure of ${}_{45}{}^{}{}_{}{}^{}\mathrm{Rh}_{}^{105}{}_{}{}^{}$, below 2 MeV in excitation, was studied by ${\mathrm{Ru}}^{104}({\mathrm{He}}^3,d){\mathrm{Rh}}^{105}$ at $E_{{\mathrm{He}}^3}=18\mathrm{}$ MeV, and by ${\mathrm{Pd}}^{108}(p,\alpha ){\mathrm{Rh}}^{105}$ at $E_p=15\mathrm{}$ MeV. An Enge split-pole spectrograph was used for high-resolution analysis of the reaction products. Particle detection for deuterons was achieved with nuclear emulsions, while position-sensitive "triode" counters were used for the $\alpha$ particles. Targets were kept thin enough to permit total experimental resolutions of 12-13 keV. Comparison of 17 measured (${\mathrm{He}}^3,d$) angular distributions with nonlocal, finite-range distorted-wave Born-approximation (DWBA) calculations indicated a predominance of $l=2\mathrm{}$ transfers, and yielded $J^{\pi }$ limits for the more strongly excited states. Differential ${\mathrm{Pd}}^{108}(p,\alpha ){\mathrm{Rh}}^{105}$ cross sections were obtained over the angular range of from 8 to 100° and complement the (${\mathrm{He}}^3,d$) measurements, frequently exciting levels not seen in proton stripping. DWBA triton-cluster transfer calculations reproduce the empirically observed $l=1\mathrm{} j$ dependence. A weaker, but detectable, $j$ dependence is predicted for $l=3\mathrm{}$. The observed ${\mathrm{Rh}}^{105}$ energy-level scheme is compared with weak-coupling-model expectations and the results of earlier $\beta$-decay studies.