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An extended analysis of the reaction mechanisms involved within deuteron interaction with nuclei, namely the breakup, stripping, pick-up, pre-equilibrium emission, as well as the evaporation from fully equilibrated compound nucleus, is presented, stressing out the key role of the direct interactions. Particular comments concern the deuteron breakup, a comparison of the corresponding parametrization predictions involved in actual model calculations and those of the microscopical models being shown. The overall agreement between the measured data and model calculations validates the description of nuclear mechanisms taken into account for the deuteron-nucleus interaction. Consequently, the lack of direct interactions (especially of the breakup mechanism) in the theoretical frame of the deuteron surrogate reactions should be considered among the main reasons of the failure of associated validation tests. [ABSTRACT FROM AUTHOR]

Further high-precision measurements of α-induced reactions on 64Zn, 108Cd,113,115In, 121,123Sb, and 191,193Ir below the Coulomb barrier have been considered within statistical-model analyses using the previous optical potential. The focus of the work is on eventual uncertainties and/or systematic errors of the OMP assessment at low energies due to the limits in the knowledge of the rest of nuclear model parameters. These parameters were analyzed anyway in advance using independent data, particularly γ-ray strength functions, including their uncertainties. [ABSTRACT FROM AUTHOR]

A competition of the low-energy Coulomb excitation (CE) with the compound nucleus (CN) formation in α-induced reactions below the Coulomb barrier has recently been assumed in order to make possible the description of the latter as well as the α-particle emission by the same optical model (OM) potential. However, we show in the present work that the corresponding partial waves and integration radii provide evidence for the distinct account of the CE cross section and OM total-reaction cross section σR. Thus the largest contribution to CE cross section comes by far from partial waves larger than the ones contributing to the σR values. Finally, effects of statistical model parameters are comparatively discussed. [ABSTRACT FROM AUTHOR]

An extended analysis of the nuclear reaction mechanisms involved within deuteron interaction with nuclei, namely the breakup, stripping, pick-up, pre-equilibrium emission, and evaporation from fully equilibrated compound nucleus, is presented in order to highlight the importance of the direct mechanisms still neglected in the analysis of deuteron-induced surrogate reactions. Particularly, the dominance of the breakup mechanism at low energies around the Coulomb barrier should be considered in the case of (d,x) surrogate reactions on actinide target nuclei. [ABSTRACT FROM AUTHOR]

An updated optical potential is thus provided for ɑ-particles on nuclei within the mass number range 45≤A≤209, below the Coulomb barrier (B), on the basis of recent high-precision measurements of ɑ-particle induced reaction data below B that made possible the understanding of actual limits and possible improvement of the ɑ-particle optical-model potentials. The main revision concerns actually only the surface imaginary potential depth at the lowest ɑ-particle energies well below B, and in fact only for the mass range above A~130. A further regional point is the underestimation of reaction cross sections for the rare-earth nuclei by using the spherical optical potential unless a 7% larger value of the surface imaginary potential radius is taken into account. Involvement of this potential for further description of both the scattering and ɑ-particles induced reactions is moreover discussed in the present work, of equal interest for nuclear astrophysics and nuclear technology for fusion devices. [ABSTRACT FROM AUTHOR]

The high precision of recent measurements for low-energy α-particle elastic-scattering as well as induced-reaction data makes possible the understanding of actual limits and possible improvement of the global optical model potentials parameters. Involvement of recent optical potentials for reliable description of both the elastic scattering and emission of α-particles, of equal interest for nuclear astrophysics (NA) and nuclear technology (NT) for fusion devices, is discussed in the present work. [ABSTRACT FROM AUTHOR]

The 'Neutrons for Science' (NFS) facility will be a component of SPIRAL-2, the future accelerator dedicated to the production of very intense radioactive ion beams, under construction at GANIL in Caen (France). NFS will be composed of a pulsed neutron beam for in-flight measurements and irradiation stations for cross-section measurements and material studies. Continuous and quasi-monokinetic energy spectra will be available at NFS respectively produced by the interaction of deuteron beam on thick a Be converter and by the 7Li(p,n) reaction on a thin converter. The flux at NFS will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV to 40 MeV range. NFS will be a very powerful tool for physics and fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. [ABSTRACT FROM AUTHOR]

In order to reduce the deviation of calculated-to-experimental activity (C/E) following benchmark experiments with pure W irradiated by 14-MeV neutrons, of interest for safety aspects and waste management of power plants, a detailed analysis of the activation cross sections was carried out using the computer codes EMPIRE-II and TALYS as well as local parameter sets within the STAPRE-H code. The sensitivity of the calculated cross sections to various model parameters is derived and discussed in connection with improving the C/E of the benchmark experiment. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Semi-microscopic and phenomenological deuterium-nucleus optical potentials have been involved within the analysis of the elastic scattering of deuterons on 6,7Li for energies up to 50 MeV, of interest for calculations of the D-Li neutron source term. Energy-dependent optical potential parameter sets have been obtained. Specific cluster structure effects for d+6Li interaction have been taken into account also by means of the coupled reaction channels method. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Following a semi-microscopic and phenomenological analyses of α-particle elastic scattering on A∼100 nuclei at energies below 32 MeV, a regional optical potential is involved in (n,α) reaction cross-sections analysis for the stable Mo isotopes. Focus on the uncertainties in the OMP parameters found to describe the α-particle emission from excited compound residual nuclei is thus obtained, looking for understanding of the related questions on the basis of microscopic models. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]