The structure of 29Si is studied in a model which couples a neutron onto low-lying core states of 28Si. Very satisfactory agreement is obtained for energy levels, E2 transition rates, and spectroscopic factors. The splitting of the 28Si dipole strength is then investigated using a particle–core and hole–core interaction derived from this 29Si study, and the effect of various approximations is examined.
We investigate the electric dipole ([Formula: see text]) structure properties of the deformed [Formula: see text]Nd nuclei in the giant dipole resonance (GDR) region within the framework of the quasiparticle random-phase approximation (QRPA). Translational and Galilean invariance (TGI) QRPA with separable isovector dipole–dipole residual interaction have been employed for the calculations. We have computed the photoabsorption cross-section and then we have compared with the experimental data. Our calculations revealed that while the photoabsorption cross-section shows a Lorentzian line in the neighborhood of spherical geometry, it starts to shift to an asymmetric shape by increasing deformation in [Formula: see text]Nd isotopes by increasing neutron number. In addition to this, we have also observed that the splitting of the [Formula: see text] strength distribution and the separation between [Formula: see text] and [Formula: see text] branches are increasing. We have calculated the contribution of the electric and magnetic parts of total dipole strength up to 20[Formula: see text]MeV for the nuclei of interest. This calculation shows that the electric part dominates the total dipole strength and [Formula: see text] excitation dominates the electric part.
The giant dipole resonance (GDR) in deformed nuclei is analyzed using the self-consistent separable random-phase-approximation (SRPA) with Skyrme forces SkT6, SkM*, SLy6 and SkI3. The deformed nuclei 150 Nd and 238 U are used as representative rare-earth and actinide samples. Dependences of the dipole strength distributions on some basic characteristics of the Skyrme functional and nuclear matter properties (isoscalar and isovector effective masses, time-odd contributions) are discussed. Particular attention is paid to the fragmentation structure of the GDR strength which is shown to depend sensitively to spin-orbit intruder states with large angular momentum.
Mictrorons are accelerators of electrons and are simultaneous sources of bremsstrahlung
photon flux and fission neutrons. In 1982, a microtron of seventeen trajectories
Microtron MT - 17 was put into operation at the National Institute of Physics of Vietnam.
Though very modest, microtons are very useful for developing countries such as Vietnam
in both fundamental and applied physics research. During the recent years by using the
above mentioned MT - 17 and microtrons from other institutes we have carried out different
investigations. In this report we present some results obtained in the studies of photonuclear
reactions and photon activation analysis in the giant dipole resonance region.