[en] The neutron decay of the giant multipole resonance region from 9 to 15 MeV of excitation energy in /sup 208/Pb has been studied. Neutron branching ratios for the decay to the ground state or to the low-lying excited states of /sup 207/Pb were measured as a function of the excitation energy of /sup 208/Pb and compared to Hauser-Feshbach calculations. While the neutron branching ratios from the isoscalar quadrupole resonance are reproduced by the calculations, the ratios from excitation energies above 12.5 MeV show a large excess with respect to the statistical predictions

[en] Spectroscopic data for all nuclei with mass number A = 191 have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented. This evaluation for A = 191 supersedes the earlier one by E. Browne (80Br16), published in Nuclear Data Sheets 30, 653 (1980). copyright 1989 Academic Press, Inc

[en] In this paper we studied pb(n,2n)reaction including neutron emission spectra from differential and integral aspects. New measurement have been done at 14.1 MeV, and compared with those by Takahashi et al. Theoretical calculation using the multistep Hauser-Feshbach theory with the preequilibrium process effect (GNASH code) which reproduced the experimental cross section rather satisfactorily. Deduced (n,2n) cross section was discussed in conjunction with our new lead shell transmission experiment for 14 MeV neutrons. (author)

[en] States in doubly odd /sup 218/Ac have been studied using in-beam α-, γ-, and e^--spectroscopy techniques mainly through the /sup 209/Bi(/sup 12/C,3n)= fusion-evaporation reaction. /sup 218/Ac shows a band structure, with interleaved states of alternating parities connected by enhanced B(E1) transitions, which is strikingly similar to the one in its isotone /sup 217/Ra

[en] Precise K and total internal conversion coefficients for the 1063.6 keV transition as well as γ- and K conversion electron intensity ratios of the 1063.6 and 569.6 keV transitions of ²⁰⁷Pb are derived from earlier measurements. The recommended values are α_K¹⁰⁶³ = 0.0945±0.0022, α_T¹⁰⁶³ = 0.126±0.003, I_γ¹⁰⁶³/Iγ⁵⁶⁹ = 0.758±0.004 and I_e¹⁰⁶³/I_e⁵⁶⁹ = 4.58±0.05. Both internal conversion coefficients deviate slightly from the theoretical values as expected. (orig.)

[en] Mass distributions of fission fragments have been measured for the reaction of ¹⁹F on ¹⁹⁷Au as a function of scattering angle. The mean fragment mass is dependent on the scattering angle, the asymmetry increasing with increasing projectile energy. (orig.)

[en] Multiple neutron-capture measurements on ¹⁹³Ir have populated numerous low-spin positive-parity states in ¹⁹⁵Ir. These states form a complete set of 1/2, 3/2, 5/2 states with σ=13/2, 11/2 and τ=1/2, 3/2, 5/2 expected in a boson-fermion symmetry. (author)

[en] The absolute electrofission cross section of /sup 209/Bi was measured in the energy range 43--250 MeV; the photofission cross section was deduced by means of the virtual-photon technique in the same energy range. The analysis of the fission probability, which was estimated from the photofission cross section and photoabsorption cross sections available in the literature, showed that /sup 209/Bi undergoes fission through compound nucleus formation for energies between the threshold and the Δ region. It was found that Levinger's modified quasi-deuteron model cross section accounts for all the compound nucleus cross section, even at energies well above the pion threshold. The ineffectiveness of the pion photoproduction excitation mechanism in inducing fission of /sup 209/Bi could be explained in terms of the role played by the pion mean free path inside the nucleus

[en] We have determined the ground-state photon decay probability and the branching ratios to a number of low-lying states as a function of excitation energy in /sup 208/Pb up to /similar to/15 MeV. Results for the giant quadrupole resonance at 10.6 MeV include determination of a ground-state electromagnetic transition strength B(E2)up-arrow = 5800 +- 1600 e²fm⁴ and observation of strong suppression of the E1 transition from the resonance to the 3^- state at 2.6 MeV. These results confirm the common assumption of the predominately isoscalar character of the 10.6-MeV resonance. Ground-state gamma coincidences enable us to isolate the isovector giant dipole resonance, which is too weak to be seen in singles, and to test models for its excitation in heavy-ion scattering

[en] We perform a global analysis of intermediate energy nucleon plus /sup 208/Pb scattering data using the Dirac phenomenology. Proton elastic differential cross sections, analyzing powers, spin rotation functions, and total reaction cross sections, together with neutron total cross sections, spanning an incident energy range of 80--800 MeV, are used in the determination of a Dirac scalar-vector global potential. Two of six energy dependencies studied are selected to construct best-fit nucleon-nucleus potentials for the reduced incident-energy interval of 95--300 MeV. These potentials reproduce the experimental data uniformly within the reduced energy interval. Explicit values for the isovector strengths of the nucleon-nucleus potential are given. The correlations and ambiguities among the parameters of the potentials are studied. Predictions are made for the elastic differential cross section and spin observables for neutron plus /sup 208/Pb scattering