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Cross sections for the 174Hf(n, 2n)173 Hf and 176Hf(n, 2n)175Hf reactions have been measured on the 5.5-MV Van de Graaff tandem accelerator of National Centre for Scientific Research "Demokritos" in Athens, in the neutron energy region from 8.8 to 11.0 MeV, using the activation technique. An experimental method to account for the contamination of the 176Hf(n, 2n) reaction by the 176Hf(n, λ) reaction activated by the parasitic neutrons of the beam is presented. Statistical model calculations have also been performed using the nuclear-reaction codes EMPIRE-II and TALYS. The results and effects of the nuclear input parameters as well as pre-equilibrium emission are discussed in detail. [ABSTRACT FROM AUTHOR]

In the present work, the 197Au(n,2n) reaction cross section is experimentally determined relative to the 27Al(n,α)24Na reaction at incident neutron energies of 9.0-10.5 MeV by means of the activation technique. The quasimonoenergetic fast neutron beam was produced via the 2H(d,n)3He reaction at the 5.5-MV Tandem Van de Graaff accelerator at the National Centre of Scientific Research (NCSR) "Demokritos" and was studied to determine the contribution of background "parasitic" neutrons using the multiple foil activation technique and the SULSA unfolding code. The cross sections for the population of the second isomeric state (12-) of 196Au and the sum of the ground (2-) and first isomeric state (5-) population cross sections were independently determined. Auxiliary Monte Carlo simulations were performed with the MCNP code. Theoretical calculations of the above cross sections in the 8-25 MeV region were carried out with the use of the STAPRE-F, EMPIRE, and TALYS codes, which were also compared in their implementation of the generalized superfluid model. The theoretical results are compared with previous work in the same mass region, and the strong dependence on the level scheme of the nuclei involved was revealed. [ABSTRACT FROM AUTHOR]

Abstract: The differential cross-sections of the 11B(d, α 0, α 2,p0) reactions for the determination of the depth distribution of boron in near-surface layers of materials have been determined in the projectile energy region E d,lab =900−1200keV. The experiment was carried out in energy steps of 25keV and for four detector angles between 140° and 170° (in steps of 10°). The obtained experimental data are suitable for Nuclear Reaction Analysis (NRA) studies. A qualitative discussion of the observed cross-section variations through the influence of broad resonances in the d+ 11B system is also presented. The results are also compared to data from literature, when present, and are validated through a benchmarking experiment using a high purity thick B4C target. [Copyright &y& Elsevier]

Recent accurate data obtained for the isomeric cross section of the 197Au(n, In) reaction provide a valuable opportunity to consider the question of the effective moment of inertia of the nucleus within a local consistent model analysis of all available reaction data for the 197Au target nucleus. Thus, a definite proof of a moment of inertia equal to that of the rigid-body has been obtained for the 196Au nucleus, while indications infer about half the rigid-body for 194Ir. [ABSTRACT FROM AUTHOR]

Neutron-induced fission reactions play a crucial role in a variety of fields of fundamental and applied nuclear science. In basic nuclear physics they provide important information on properties of nuclear matter, while in nuclear technology they are at the basis of present and future reactor designs. Finally, there is a renewed interest in fission reactions in nuclear astrophysics due to the multi-messenger observation of neutron star mergers and the important role played by fission recycling in r-process nucleosynthesis. Although studied for several decades, many fundamental questions still remain on fission reactions, while modern applications and the development of more reliable nuclear models require high-accuracy and consistent experimental data on fission cross sections and other fission observables. To address these needs, an extensive fission research programme has been carried out at the n_TOF neutron time-of-flight facility at CERN during the last 18 years, taking advantage of the high energy resolution, high luminosity and wide energy range of the neutron beam, as well as of the detection and data acquisition systems designed for this purpose. While long-lived isotopes are studied on the 185 m long flight-path, the recent construction of a second experimental area at a distance of about 19 m has opened the way to challenging measurements of short-lived actinides. This article provides an overview of the n_TOF experimental programme on neutron-induced fission reactions along with the main characteristics of the facility, the various detection systems and data analysis techniques used. The most important results on several major and minor actinides obtained so far and the future perspectives of fission measurements at n_TOF are presented and discussed. [ABSTRACT FROM AUTHOR]

Abstract: The first reaction spectroscopy on the ground state structure of 33Mg through the measurement of the longitudinal momentum distribution from the one-neutron removal reaction using a C target at is reported. The experiment was performed at the FRS, GSI. The distribution has a relatively narrow width ( (FWHM)) and the one-neutron removal cross-section is . An increased contribution from the orbital is required to explain the observation showing its lowering compared to existing model predictions. This provides new information regarding the configuration of 33Mg and the island of inversion. [Copyright &y& Elsevier]