[en] The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. The method is applied to the ¹⁵⁵Gd(n,γ) reaction. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ) cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications. (authors)

[en] It is demonstrated that available experimental information on photon strength functions (PSFs) at energies below and about 10 MeV is often incorrect. Problems that occur during the extraction of PSFs from (n,γ), (γ,γ'), and ³He-induced reactions are discussed. (authors)

[en] In studies of nucleon elastic scattering, a correction to the microscopic optical potential built from Melbourne g-matrix was found to be necessary at low nucleon incident energy. Indeed, at energies lower than 60 MeV, the absorption generated from Melbourne g-matrix is too weak within 25%. Coupling to collective excited states of the target nucleus are not included in the g-matrix and could explain the missing absorption. We propose to calculate this correction to the optical potential using the Gogny D1S effective nucleon-nucleon interaction in the coupling to excited states of the target. We use the Random Phase Approximation (RPA) description of the excited states of the target with the same interaction. (authors)

[en] The KRIF library of the neutron-, proton- and gamma-spectra emitted by the nuclei excited up to 500 MeV is presented. The KRIF contains information for about 2000 emitters which are the fragments of the ten targets fission (from ²⁰⁸Pb to ²⁴¹Cm) induced by the nucleons with the energies up to 3 GeV. (authors)

[en] We present preliminary results from a measurement of nuclear level densities and the γ-ray strength of light Sc (Sc⁴³, Sc⁴⁵) and Ti (Ti⁴⁴, Ti⁴⁵ and Ti⁴⁶) isotopes using the Oslo Method. The article begins with a presentation of the experimental setup. (authors)

[en] We analyzed experimental data obtained for the mass distribution of fission fragments in the reactions ³⁶S+²³⁸U and ³⁰Si+²³⁸U at several incident energies, which were performed by the JAEA group. Using the dynamical model with the Langevin equation, we precisely investigate the incident energy dependence of the mass distribution of fission fragments. We also consider the fine structures in the mass distribution of fission fragments caused by the nuclear structure at a low incident energy. It is explained why the mass distribution of fission fragments has different features in the two reactions. The fusion cross sections are also estimated. (author)

[en] We consider three methods for determining neutron nonelastic cross sections: direct measurement by transmission of neutrons through a spherical shell; subtraction of the angle-integrated elastic cross section from the total cross section; and a modification of the subtraction technique using Wick's limit that in favorable cases can significantly reduce the errors in the subtraction method. We show new results using the modified subtraction technique for nonelastic cross sections at 21.6 MeV neutron energy over a wide mass range, and discuss criteria that should be satisfied in order for the modified subtraction technique to be reliable. (author)

[en] The evaluation of microscopic alpha-nucleus optical potentials within the nuclear structure approach is revisited. This approach seems best suited at low energies relevant for nucleosynthesis, but no further developments were performed for more than two decades. Here, a report on the first steps of a revival of the nuclear structure approach, i.e. numerical implementation of the formulae for the imaginary part, is given. We outline in chapter 2 the formalism of the nuclear structure approach of Dermawan, Osterfeld and Madsen together with some details on involved quantities. In chapter 3 we discuss the numerical implementation and show first results of the calculation of the imaginary part of the α-¹⁶O optical potential. Finally in chapter 4 the results are summarized and an outlook to further research is given

[en] The exciton model of pre-equilibrium decay was originally formulated for the emission of nucleons, and the other kinds of ejected particles have been introduced afterwards. However, clusters and gammas have not been yet treated simultaneously in competition. In connection with series of experiments using the 'Oslo method', we feel that such extension of calculations may be useful and we try to fill in this gap. To this aim, we employ the updated version of the Iwamoto-Harada-Bisplinghoff model to study the emission of γ in coincidence with clusters. It is shown that at excitation energies of several tens of MeV, practically all emission of γ at energies lower than 10 MeV comes after the α emission and it is practically from equilibrated compound nucleus

[en] The nucleus-nucleus potential and energy dissipation in fusion reactions are obtained from microscopic mean-field dynamics. The deduced potentials nicely reproduce the one extracted from experimental data. Energy dissipation shows a universal behaviour between different reactions. Also, the dispersion of mass distribution in transfer reaction is investigated in a stochastic mean-field dynamics. By including initial fluctuations in collective space, the description of the dispersion is much improved compared to that of mean field only. The result is consistent with the macroscopic phenomenological analysis of the experimental data. (authors)