Coulomb Excitation ofCu63andCu65

Properties of levels Coulomb excited in ${\mathrm{Cu}}^{63}$ and ${\mathrm{Cu}}^{65}$ with 4- to 8-MeV alpha particles have been investigated. The $B\left(E2\mathrm{}\right)\text{'}\mathrm{s}$ for excitation determined from the yields of gamma rays observed in singles and coincidence spectra for the (668±4)-, (961±6)-, and (1323±16)-keV levels in ${\mathrm{Cu}}^{63}$ are, respectively, (1.16±0.12), (3.49±0.34), and $(4.0\mathrm{}\pm 0.5)\times {10}^{-50\mathrm{}}{e}^2$ ${\mathrm{cm}}^4$; for the (771±7)-, (1115±11)-, and (1474±19)-keV levels in ${\mathrm{Cu}}^{65}$, they are (1.02±0.11), (3.45±0.38), and $(4.3\mathrm{}\pm 0.8)\times {10}^{-50\mathrm{}}{e}^2$ ${\mathrm{cm}}^4$. These results give $B\left(E2\mathrm{}\right)\text{'}\mathrm{s}$ for decay which are 13 to 16 times the single-particle $B\left(E2\mathrm{}\right)\mathrm{}$. This similarity of $B\left(E2\mathrm{}\right)\text{'}\mathrm{s}$ was predicted by de Shalit for levels which result from the coupling of the odd particle to the first excited state of the even-even core. From angular correlation studies the 961- and 1115-keV levels have been assigned spin $\frac{5}{2}$ and the 1323-keV level spin $\frac{7}{2}$. Mixing ratios obtained from these measurements along with the $B\left(E2\mathrm{}\right)\text{'}\mathrm{s}$ establish values of 0.09 and 0.4 ${\left(\frac{e\hslash }{2} \mathrm{Mc}\right)}^2$ for the $B\left(M1\mathrm{}\right)\text{'}\mathrm{s}$ of the 961- and 1115-keV transitions.