Electromagnetic response of light nuclei

We show examples of neutron capture, photo dissociation and Coulomb dissociation processes, relevant for studying nuclear structure properties of some light nuclei. In the case of the neutron capture, we show how interference effects among the direct and resonance processes can be accounted for. The same interference effect is shown to play an important role in the photo dissociation of 9Be, for excitation energies just above the neutron emission threshold. Finally, the Coulomb dissociation of radioactive projectiles is shown to provides basic structure information on neutron rich exotic systems. The example of the 19C halo structure is shown.Comment: Invited talk at the International Symposium on "Capture Gamma-ray Spectroscopy and Related Topics" Santa Fe, New Mexico, August 29-September 3, 199

Exotic Properties of Light Nuclei and their Neutron Capture Cross Sections

We have investigated the implications of the neutron halo configuration, observed in the ground-state of some neutron-rich light nuclei, on neutron radiative transition processes. In particular, we have studied the influence of the neutron halo on the direct radiative capture (DRC) process. The energy dependence as well as the strength of E1 emission due to incident p-wave neutrons is strongly influenced by the halo configuration of the residual nucleus capturing state. We have compared the calculated 10Be(n,gamma)11Be DRC cross section with that derived from the experiment in the inverse kinematics (Coulomb dissociation of 11Be). We show from the comparison that some important information on the structure of the halo nucleus 11Be can be derived.Comment: Contribution to the 4th International Seminar on Interaction of Neutrons with Nuclei, Dubna (Russia), April 199

The s-process branching at 185W

The neutron capture cross section of the unstable nucleus 185W has been derived from experimental photoactivation data of the inverse reaction 186W(gamma,n)185W. The new result of sigma = (687 +- 110) mbarn confirms the theoretically predicted neutron capture cross section of 185W of sigma = 700 mbarn at kT = 30 keV. A neutron density in the classical s-process of n_n = (3.8 +0.9 -0.8} * 1e8 cm-3 is derived from the new data for the 185W branching. In a stellar s-process model one finds a significant overproduction of the residual s-only nucleus 186Os.Comment: ApJ, in pres

Stellar neutron capture cross sections of ⁴¹K and ⁴⁵Sc

The neutron capture cross sections of light nuclei (