Elastic and inelastic scattering of 16O and 12C by 24Mg near the Coulomb barrier

Angular distributions for ¹⁶O + ²⁴Mg and ¹²C + ²⁴Mg elastic and inelastic (2⁺, 1.37 MeV state in ²⁴Mg) scattering have been measured at energies spanning the Coulomb barrier. Apart from the structure typical of strong destructive Coulomb-nuclear interference, the data exhibit some additional specific features. Coupled channel calculations were performed, along with DWBA calculations to analyse the data using fixed coupling strengths deduced from the results of Coulomb excitation work. The importance of higher-order effects such as reorientation, is demonstrated.     

The (3He,n) reaction in the lower 2s1d shell

The two-proton transfer reaction (³He, n) has been measured on four gas targets, ¹⁶O, ¹⁸O, ²⁰Ne, and ²²Ne, with an incident ³He energy of 18.3 MeV. The data were taken with a neutron time-of-flight spectrometer in the angular range 0° to 40° c.m. The results for selected transitions are compared to DWBA predictions using shell-model spectroscopic amplitudes. In addition, the data for the ¹⁸O(³He, n)²⁰Ne reaction are compared to predictions of the SU(3) strong coupling model.     

Compound transfer and direct transfer reactions induced by 17O on 13C

The elastic scattering, inelastic scattering, single-neutron transfer reactions ¹³C(¹⁷O, ¹⁶O) ¹⁴C, ¹³C(¹⁷O, ¹⁸O)¹²C and ¹³C(¹⁷O, ¹⁸O_{2+, 1.98})¹²C, and seven other exit channels which involve ⁷Li, ⁹Be, ¹¹B and ¹⁵N have been measured for the system ¹⁷O+¹³C at 12.9 and 14 MeV c.m. It is shown that all reactions mentioned above have significant contributions from compound nuclear decay, following fusion of projectile and target.     

Elastic 3He scattering from even Ar isotopes and backward-angle anomalies in the systematics of elastic 3He scattering

Angular distributions have been measured for ³He elastic scattering from ^{36, 38, 40}Ar at 26.5 MeV and from ³⁶Ar and ⁴⁰Ca at energies between 24.5 and 28 MeV. This scattering clearly shows features of “anomalous” backward-angle scattering, which is discussed in the systematics of ³He scattering from heavier target nuclei. The data for “anomalous” scattering can be described by optical potentials which show features significantly different from those of “normal” scattering. These features are smaller radius parameters for the real optical potential and a strongly reduced volume integral for the imaginary potential.     

A numerical study of resonance contributions to nuclear sum rules

The modified form of the nuclear sum rule which was proposed by Berggren is applied to a simple solvable problem and it is demonstrated, within the confines of that problem, that the continuum contribution to the sum rule is often dominated by the contribution from a few resonances, just as Berggren had anticipated. It is further shown that the bound, virtual and resonant states of the Hamiltonian considered form a complete set of states in terms of which the internal region of space can be expanded.     

Reaction spectroscopy at fragmentation beam energies – recent advances in studies of two-nucleon removal

Final-state-exclusive two-nucleon removal reaction data from fast fragmentation beams can provide a demanding test of the microscopic two-nucleon transition densities calculated from large-basis shell model wave functions. The sensitivity of measured partial cross sections to pairing and other correlations is discussed. It is also suggested that the widths of the momentum distributions of these partial cross sections will exhibit a strong dependence on the final-state of the residue and the projectile structure.     

Two-fluid model description of isovector giant resonances in fast rotating nuclei

Isovector giant resonances of arbitrary multipolarity in fast rotating nuclei are studied by solving the inviscid two-fluid equation of relative motion in a rotating frame of reference. Both Coriolis and centrifugal forces are taken into account. The resulting expressions display in a quite simple way general features of giant multipole resonances of fast rotating nuclei, in addition to a good agreement with other calculations for the giant dipole resonance. Typical values for the resonance energies and their fragmentation due to nuclear deformation and rotation are given. In particular, enormously large resonance splitting should occur in the superdeformed states.     

Angular momentum transfer and partition in the deep-inelastic reaction 664 MeV 84Kr + natAg

In- and out-of-plane angular distributions have been measured for sequential α-decay from target-like fragments produced in fully relaxed heavy-ion collisions. At angles equal to or larger than the target-recoil direction, the α-particle energy spectra are evaporation-like and the in-plane angular distributions are consistent with isotropy in the rest frame of the target recoil. The out-of-plane distributions exhibit an anisotropy of approximately two. Fragment spins were extracted from these distributions as a function of mass asymmetry. These spins are in agreement with those obtained from a simultaneous γ-ray multiplicity measurement. Both the fragment kinetic energies and intrinsic spins are consistent with rigid rotation of an intermediate complex consisting of two substantially deformed spheroids in near proximity.     

Elastic scattering of vector polarized deuterons by 4He

The vector analyzing power iT₁₁ for deuterons elastically scattered by ⁴He has been measured for c.m. angles between 51.8° and 158.9° and deuteron energies in the range 11.5 to 17 MeV. The results show that d-α scattering is a convenient analyzer for deuteron vector polarization in the energy range investigated, since the angular dependence of iT₁₁ is fairly insensitive to energy and the magnitude of iT₁₁ is quite large at some angles.