I.J. Thompson

Core excitation in 12Be

Abstract Motivated by much recent discussion of the N =8 neutron shell closure, we review the theoretical description of 12 Be within a three-body (n+n+ 10 Be) model with core excitation. Agreement with recently deduced 〈 11 Be| 12 Be〉 spectroscopic factors requires a smaller deformation of the 10 Be core in 12 Be than in 11 Be, with a reduced role for core excitation. Observables for the ground state and 2 + , 1 − and 0 + 2 excited states of 12 Be are presented. Limitations and improvements of the model are discussed.

The potential of the loosely bound 9Be from 209Bi elastic scattering: unusual behaviour at near threshold energy

Abstract Precise elastic scattering measurement were done at the Coulomb barrier for the system 9 Be+ 209 Bi fromxa040 to 48xa0MeV in 2xa0MeV intervals and 3.5° steps. The deduced Woods–Saxon potential shows a very unusual behaviour that could be connected to the breakup of the weakly bound projectile expected to have a large cross section. The same potential also reproduces the observed inelastic scattering.

Breakup of 9Be on 209Bi above and near the Coulomb barrier as a molecular single-particle effect: Its influence on complete fusion and scattering

Abstract The breakup of the 9 Be projectile on the 209 Bi target at bombarding energies above and near the Coulomb barrier is studied in the adiabatic two-center shell model approach. The effect of 9 Be → n +2α breakup channel on complete fusion, elastic and inelastic cross sections is investigated. Results show that the breakup of the projectile 9 Be could be due to a molecular single-particle effect shortly before the colliding nuclei reach the Coulomb barrier.

Fusion of weakly bound projectiles around the Coulomb barrier

The effect of breakup of weakly bound projectiles on fusion is studied using two approaches. The first approach based on the coupled discretised continuum channel (CDCC) formalism is used for 11Be+208Pb, while the second one based on the two-centre shell model (TCSM) is used for 9Be+209Bi, 64Zn. The CDCC approach describes the breakup in terms of inelastic excitations of the projectile to the continuum, while the breakup is described by molecular single-particle effects in the TCSM approach.

The effects of core excitation in the breakup of exotic nuclei

Breakup of exotic nuclei is discussed within the context of the recently developed XCDCC (eXtended Continuum Discretized Coupled Channel) model. The method is applied to the breakup of 11 Be into 10 Be + n + γ on a 9 Be target. Interference between the multi-configurations of the projectile is observed as well as dynamical excitation of the core through the interaction with the target.

6Li excitation above the breakup threshold in the 6Li+208Pb system at Coulomb barrier energies

The excitation energy of the 6Li+208Pb system has been studied at several energies around the Coulomb barrier with a large solid angle detector array. The α + d/6Li* excitation above the breakup threshold (Sd = 1.475 MeV) has been deduced from the invariant mass of the α + d system. All the collected data show a similar behaviour: the cross sections are peaked at around 1 MeV above the threshold and they have an exponential decay on the high energy side, suggesting a direct breakup process. A Monte‐Carlo simulation of the whole reaction mechanism has been performed in order to check the validity of data analysis procedure and to study the influence of the set‐up geometry onto the experimental results.Two different theoretical approaches, the former based on fully quantum mechanical Coupled Channel calculations and the latter based on simpler semi‐classical calculations, treating the relative motion of the α + d cluster structure along a classical trajectory, reproduce both in shape and absolute value the ...