Measurement of the $$^{232}$$Th(n,f) cross section with quasi-monoenergetic neutron beams in the energy range 2–18 MeV

The fission cross section of $$^{232}$$ 232 Th has been measured at fast neutron energies, using a setup based on Micromegas detectors. The experiment was performed at the 5.5 MV Van de Graaff Tandem accelerator in the neutron beam facility of the National Centre for Scientific Research “Demokritos”. The quasi-monoenergetic neutron beams were produced via the $$^{3}$$ 3 H(p,n), $$^{2}$$ 2 H(d,n) and $$^{3}$$ 3 H(d,n) reactions, while the $$^{238}$$ 238 U(n,f) and $$^{235}$$ 235 U(n,f) reactions were used as references, in order to acquire cross-section data points in the energy range 2–18 MeV. The characterization of the actinide samples was performed via $$\alpha $$ α -spectroscopy with a Silicon Surface Barrier (SSB) detector, while Monte Carlo simulations with the FLUKA code were used to achieve the deconvolution of the $$^{232}$$ 232 Th $$\alpha $$ α peak from the $$\alpha $$ α background of its daughter nuclei present in the spectrum. Special attention was given to the study of the parasitic neutrons present in the experimental area, produced via charged particle reactions induced by the particle beam and from neutron scattering. Details on the data analysis and results are presented.

Tests of Various Scintillator Detectors in Selected Mono-Energetic Neutron Beams

In this paper we study quality of three types of organic scintillators stilbene, p-terphenyl and EJ-299-33. We used monoenergetic neutron fields with a wide range of neutron energies in PTB Braunschweig. All the tests were carried out with NGA-01 spectrometer. The results of the measurements are evaluated spectra from the spectrometer. We discuss the quality of each scintillator, such as the FWHM of the peaks.

Study of the 165Ho(n,2n)164Ho reaction at near threshold energies

The present work concerns the preliminary analysis for the study of the (n,2n) reaction channel of the 165Ho isotope at near threshold energies: 10.1, 10.4 and 10.7 MeV (Eth=8.04 MeV). The cross sections for the population of both the ground state (Jπ=1+) and the isomeric state (Jπ=6-, Eex=139.8 keV) of the 164Ho product-nucleus were measured at the afore mentioned energies via the activation technique relative to the 27Al(n,α)24Na and 197Au(n,2n)196Au reactions. The quasi-monoenergetic neutron beams were produced through the 2H(d,n)3He reaction in the 5.5 MV Tandem Van de Graaf accelerator of N.C.S.R ''Demokritos''. The preliminary experimental results are compared with theoretical predictions based on TALYS code.

Statistical model calculations of 72,73Ge(n,p) and 72,74Ge(n,α) reactions on natural Ge

Systematic experimental and theoretical investigations of the 72,73Ge(n,p)72,73 Ga and 72,74Ge(n,α)69,71Znm reaction cross sections are presented in the energy range from thresh- old to about 17 MeV neutron energy. The above reaction cross sections were measured from 8.8 to 11.4 MeV by using the activation method, relative to the 27Al(n,α)24Na refer- ence reaction. The quasi-monoenergetic neutron beams were produced via the 2H(d,n)3He reaction at the 5 MV VdG Tandem T11/25 accelerator of NCSR “Demokritos”. Statisti- cal model calculations using the code EMPIRE-II (version 2.19) taking into consideration pre-equilibrium emission were performed on the data measured in this work as well as on data reported in literature.