Yrast decay schemes from heavy ion +Ca48fusion-evaporation reactions. I.Mn54−56,Cr56, andV52−53

Abstract

Fusion-evaporation reactions induced by a beam of 25-50 MeV $^{11}\mathrm{B}$ on an isotopically enriched $^{48}\mathrm{Ca}$ target have been used to populate high-spin yrast levels in $^{54\ensuremath{-}56}\mathrm{Mn}$, $^{56}\mathrm{Cr}$, and $^{52\ensuremath{-}53}\mathrm{V}$. Measurements consisted of $\ensuremath{\gamma}$- ray excitation functions, angular distributions, $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidences, and recoil-distance and Doppler shift lifetime measurements, from which were deduced the energy levels, $\ensuremath{\gamma}$-ray branching ratios, most probable spin-parity assignments, and level lifetimes.[NUCLEAR REACTIONS $^{48}\mathrm{Ca}(^{11}\mathrm{B},xn,yp,z\ensuremath{\alpha})^{54\ensuremath{-}56}\mathrm{Mn}$, $^{56}\mathrm{Cr}$, and $^{52\ensuremath{-}53}\mathrm{V}$. $E=25\ensuremath{-}50$ MeV; measured $\ensuremath{\sigma}(E,{E}_{\ensuremath{\gamma}})$ and coin.; deduced levels; measured $\ensuremath{\sigma}({E}_{\ensuremath{\gamma}},\ensuremath{\theta})$; deduced ${J}^{\ensuremath{\pi}}$ for high-spin levels; measured RDM and Doppler shifts; deduced ${t}_{\frac{1}{2}}$, ${|M(M1)|}^{2}$ and ${|M(E2)|}^{2}$. Enriched targets, Ge(Li) detectors.]