²⁴Mg(¹⁸O, ¹⁶O)²⁶Mg reaction at E_¹⁸O=50 MeV including scattering in entrance and exit channel

Cross section angular distributions of ²⁴Mg(¹⁸O, ¹⁶O)²⁶Mg reaction at 50 MeV incident energy leading to the first four excited states in ²⁶Mg and the elastic and inelastic scattering for ¹⁸O + ²⁴Mg at 50 MeV and ¹⁶O + ²⁶Mg at 56 MeV have been measured in order to investigate the reaction mechanism of the two-nucleon transfer reaction including the analysis of incident and exit channels. The measured angular distributions were analyzed in the framework of the exact finite-range distorted-wave Born approximation. Two neutron transfer amplitudes were determined using the 2s-1d shell model amplitudes calculated by Chung and Wildenthal. The large experimental cross section in contrast to the smallness of the direct transfer amplitude and the peculiar shape of the measured angular distribution of the lowest 2₁⁺ state suggests that this level is mainly excited by two-step processes. It is shown that a coupled-channel Born approximation calculation describes successfully the angular distributions of the ground state and the 2₁⁺ state in ²⁶Mg.

NUCLEAR REACTIONS ²⁴Mg(¹⁸O, ¹⁶O)²⁶Mg, E_¹⁸O=50 MeV, measured σ(θ, E_x); ²⁴Mg(¹⁸O, ¹⁸O)²⁴Mg, E_¹⁸O=50 MeV and ²⁶Mg(¹⁶O, ¹⁶O)²⁶Mg, E_¹⁶O=56 MeV, elastic and inelastic scattering, measured σ(θ); enriched targets; optical model parameters deduced from scattering: microscopic EFR-DWBA and CCBA analysis with shell-model wave functions.