Coulomb-nuclear interference data for incident energies between 9 and 17 MeV were obtained in the form of elastic and inelastic (to the $2_1^{+}$ states) excitation functions of backscattered (θ≃172.8°) alpha particles on ${}_{}{}^{100,102,104}{}_{}{}^{}\mathrm{Ru}$. The analysis was done in a distorted-wave Born approximation within a deformed optical model approach. B(E2) values, obtained from the charge deformation lengths ${\mathrm{\delta }}^{\mathit{C}}$ extracted from the low energy data, are compatible for the three isotopes within ∼ 2σ with published values. The nuclear quadrupolar deformation lengths ${\mathrm{\delta }}^{\mathit{N}}$, obtained from the analysis of the interference region of the excitation functions, and also of one angular distribution at 22 MeV measured for ${}_{}{}^{100}{}_{}{}^{}\mathrm{Ru}$ are generally lower than the corresponding charge deformation lengths, the difference increasing with increasing A of the isotope, ${\mathrm{\delta }}^{\mathit{N}}$ being 18% lower than ${\mathrm{\delta }}^{\mathit{C}}$ for ${}_{}{}^{104}{}_{}{}^{}\mathrm{Ru}$ ($2_1^{+}$). Nuclear deformation lengths associated with the $3_1^{\mathrm{-}}$ states of ${}_{}{}^{100,102,104}{}_{}{}^{}\mathrm{Ru}$ and with the $4_2^{+}$ state of ${}_{}{}^{100}{}_{}{}^{}\mathrm{Ru}$ at 2.367 MeV were also obtained as a by-product of the present work. © 1996 The American Physical Society.

• Received 13 May 1996

DOI:https://doi.org/10.1103/PhysRevC.54.2296