Photodisintegration of 9 Be through the 1/2 + state near neutron threshold and cluster dipole resonance below giant dipole resonance was measured with quasi-monochromatic γ-ray beams produced in the inverse Compton scattering of laser photons. The cross section for the 1/2 + state is revisited, being consistent with the 2001 data. The cross section for the cluster dipole resonance is consistent with the cluster dipole sum-rule which however degenerates for the two-body (n-8 Be) and three-body(n-α-α) configurations.

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Photoneutron cross sections were measured for 58 Ni, 60 Ni, 61 Ni, and 64 Ni at energies between the one-neutron and two-neutron thresholds using quasi-monochromatic γ-ray beams produced in laser Compton-scattering at the NewSUBARU synchrotron radiation facility. The new photoneutron data are used to extract the γ-ray strength function above the neutron threshold complementing the information obtained by the Oslo method below the threshold. We discuss radiative neutron capture cross sections and the Maxwellian-averaged cross sections for Ni isotopes including 63 Ni, a branching point nucleus along the weak s-process path. The cross sections are calculated with the experimentally constrained γ-ray strength functions from the Hartree-Fock-Bogolyubov plus quasiparticle-random phase approximation based on the Gogny D1M interaction for both E1 and M 1 components and supplemented with the M 1 upbend.

Photoneutron cross sections were measured in the 209 Bi(γ , xn) reaction with x = 1-4 at energies from the neutron threshold to 40 MeV using quasimonochromatic laser Compton-scattering γ-ray beams. A novel technique of direct neutron-multiplicity sorting with a flat-efficiency detector was used. Results are compared with the positron in-flight annihilation data of Livermore and Saclay as well as with bremsstrahlung data. The present neutron yields are consistent with the latest photoactivation measurement with bremsstrahlung. The giant dipole resonance component of the total photoneutron cross section is reasonably reproduced by model calculations of the Hartree-Fock Bogoliubov plus quasiparticle random phase approximation based on the Gogny D1M interaction for both E1 and M1 components. In contrast, the quasideuteron component of the total photoneutron cross section requires a factor of ∼3 enhancement of the Levinger parameter. Furthermore, a survival of large (γ,n) cross sections above 20 MeV may indicate the surface effect on the two-component particle-hole state density. The threshold behavior of photoneutron emission is discussed in terms of the average neutron kinetic energy.