Beams of free neutrons are an important probe to analyze the structure and dynamics of condensed matter and are produced at neutron research reactors, neutron spallation sources or compact accelerator-based neutron sources (CANS). An efficient construction of CANS with a maximized neutron yield and brilliance requires reliable knowledge of the consequences of radiation-induced material damage, the predominating bottleneck of a target’s lifetime. In the framework of the Jülich High-Brilliance neutron Source project, the impact of proton- and neutron-induced material damage of a tantalum target was investigated. The Monte Carlo codes FLUKA and SRIM were utilized to extract the number of displacements per atom resulting from atomic rearrangements. The simulations performed distinctly identify the rear of the neutron target as the most vulnerable area, with the protons as main damage contributors. The minor contribution of neutrons is a material-specific phenomenon due to their high mean free path length in tantalum. Numerical results of the simulations served to calculate average and peak damage rates $${R}_{\mathrm{d}}$$ R d (dpa/s), both in turn scaled to annual displacement doses for continuous operation in a full power year (dpa/fpy). Supplemented by the literature, a minimum target lifetime $$\tau _{\min }$$ τ min of 2.6 years (33 Ah) is concluded.

Prompt gamma rays induced by inelastic scattering of fast neutrons on aluminum, titanium and copper were measured at an angle of 90o between fast neutron beam and detector of the instrument FaNGaS, operated by Jülich Centre of Neutron Science at Heinz-Maier-Leibnitz Zentrum in Garching. The fast neutron flux was 1.40 108 cm−2 s−1 with the average energy of 2.30 MeV. Intensities and neutron spectrum averaged isotopic partial cross section for production of 214 gamma lines (22 for aluminum, 72 for titanium and 120 for copper) are presented. The results are consistent with the literature data. However, the new sets of gamma lines are recommended to replace the old datasets from fast neutrons reactors with several new lines also recognizing a few false identifications. Additionally, the detection limits of aluminum, titanium, copper, iron and indium were determined as 1.0, 0.4, 0.9, 0.5 and 1.3 mg, respectively, for a counting time of 12 h.

Emission of prompt gamma rays following (n,n’), (n,p) and (n,α) reactions induced by irradiation of a calcium carbonate (CaCO3) sample with a beam of fission neutrons was investigated with a modified version of the FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) instrument operated at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching. The neutron spectrum has an average energy of 2.30 MeV and at sample position the fast neutron flux was (1.13 ± 0.04) × 108 cm−2 s−1. The measurement was performed at an angle of 90° between neutron beam and detector. In total, we claim the identification of 38 prompt gamma lines, from which we have assigned 12 to the (n,n’) reaction in calcium (7 for 40Ca, 1 for 42Ca and 4 for 44Ca), 1 to the 12C(n,n’)12C reaction, and 2 to the (n,n’) reaction in oxygen (1 for 16O and 1 for 18O). The other observed gamma lines are attributed to the 40Ca(n,p)40K reaction (20 lines) and to the 40Ca(n,α)37Ar reaction (3 lines). Relative intensities and fast neutron spectrum averaged partial cross sections of the gamma lines are presented and compared with available literature data. Our results were found to be in good agreement with available literature data but also improved and complemented it, as we have pointed out possible errors and identified new lines. Additionally, for a counting time of 12 h the detection limits of calcium, carbon and oxygen were determined as 5, 13 and 64 mg, respectively.