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Tagged neutrons are used to perform an experimental investigation of the inelastic scattering of 14.1 MeV neutrons on 23Na and 35Cl nuclei as part of the TANGRA project at the Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research. The energies and yields of γ quanta for transitions observed in the experiment are measured, and the γ angular distribution coefficients for the highest intensity γ transitions are obtained. The experimental data are compared to others in the literature.

The TALYS 1.9 program is used to calculate cross sections of processes that occur during the scattering of fast neutrons on 48Ti, 52Cr, and 56Fe isotopes. Results from model calculations are compared to data obtained in the TANGRA project using tagged neutrons from the yields of γ-quanta for Ti, Cr, and Fe isotopes, and the results from earlier experiments. Analysis of the model description’s sensitivity to the choice of the direct reaction mechanism shows the most informative characteristic from this viewpoint is the differential cross section of inelastic scattering.

The work is devoted to determining the response function of the detector NaI(Tl) for g -quanta with energy of 4.43 MeV, formed during inelastic scattering of neutrons with energy of 14.1 MeV on the nuclei 12C. In gamma spectrometry, output pulses are recorded, the amplitudes of which are proportional to the energy lost in the detection medium by incident photons. One of the main tasks of radiation detection is to restore radiation characteristics from signals measured at the outputs of detectors. For this, it is necessary to know, first of all, the general characteristics of detectors as converters of radiation into signals. The main characteristic of the detector is its response function, which can be defined as the probability that a particle with given properties generates a certain signal in the detector that will be registered by the device. The article presents the results of modeling the response function of a scintillation detector based on a NaI(Tl) crystal for gamma radiation from inelastic fast neutron scattering in order to study the mechanism of its formation.

Using the tagged neutron method at the "TANGRA" facility at Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research based on the ING-27 standard neutron generator, a study of the 14.1 MeV inelastic neutron scattering reaction on different nuclei was carried out. The angular distributions of γ - quanta accompanying inelastic neutron scattering on atomic nuclei were measured. This article presents a GEANT4-based program that allows calculating the interaction of fast neutrons with matter and simulating the experiment and also presenting the results of the experiment in a convenient and visual form. Using the written program, optimal target parameters were determined. The algorithm used by the program is given in this work. The general description of the experimental installation, data collection and processing systems is given.

The inelastic scattering of 14.1 MeV neutrons off magnesium nuclei is studied at the TANGRA facility using tagged neutrons and an ING-27 standard neutron generator. The energies and partial cross sections of visible γ transitions induced in different reactions between neutrons and magnesium nuclei are determined. The measured angular distribution of γ quanta for 24Mg is analyzed and compared to results from other experimental studies.

The results obtained by measuring the angular and energy distributions of gamma rays produced in reactions induced by the inelastic scattering of 14.1-MeV neutrons on$^{27}$Al nuclei are presented. The respective measurements were performed by the tagged-neutron method in a beam from the ING-27 compact neutron generator. The angular distributions were obtained for gamma rays emitted from the 844-keV 1/2$^{+}$, 1015-keV 3/2$^{+}$, 2212-keV 7/2$^{+}$, and 3004-keV 9/2$^{+}$ states of$^{27}$ Al nuclei.

An investigation of inelastic scattering of 14.1 MeV neutrons on an iron sample was carried out using an improved TANGRA (TAgged Neutron and Gamma RAys) setup at JINR (Dubna). The yields of the occurring $$\gamma $$ -transitions and anisotropy of the emitted $$\gamma $$ -rays were measured using the tagged neutron method. The setup with a high-purity germanium (HPGe) detector was used to obtain the energy spectrum of $$\gamma $$ -rays. The setup with 18 BGO scintillation detectors positioned in a circle around the sample was used to obtain angular distributions of $$\gamma $$ -rays. A detailed $$\gamma $$ -spectrum for $$(n,X\gamma )$$ reactions was obtained and the $$\gamma $$ -ray angular distribution was measured for the 847 keV and 1238 keV $$\gamma $$ -transitions. The distribution was fitted by Legendre polynomials up to fourth order and the angular distribution coefficients $$a_2$$ , $$a_4$$ were extracted. A comparison with other published experimental results is given. Model calculations using computer code TALYS 1.9 were performed. The results of calculations are discussed in comparison with the obtained experimental data.

The results obtained by measuring the angular and energy distributions of gamma rays originating from the inelastic scattering of 14.1-MeV neutrons by carbon and oxygen nuclei are presented. The measurements in question were performed by the tagged-neutron method in a beam of an ING-27 standard portable neutron generator. The angular distributions of gamma rays emitted by the 2+ state of 12С at 4.43 MeVand the 3− state of 16O at 6.13 MeV were obtained.

The response function of the BGO, NaI (Tl) and LaBr 3 (Ce) scintillation detectors to monoenergetic gamma quanta was built on the basis of Monte Carlo simulations using the GEANT4 toolkit and calibration measurements with gamma radiation sources of different energies. The response function consists of seven components: the first six constitute the detector’s response to a direct hit of monoenergetic gamma radiation and depend on the properties of the detector (size, material, energy resolution, etc.), and the seventh component represents the effect of surrounding materials on the measured gamma spectrum. For each component of the function, the analytical form of the energy dependence is determined and its parameters are found when registering gamma quanta with energies in the range from 0.3 MeV to 10 MeV.

The characteristic gamma radiation from the interaction of 14.1 MeV neutrons with a natural silicon sample is investigated with Tagged Neutron Method (TNM). The anisotropy of gamma-ray emission of 1.779 MeV was measured at 11 azimuth angles with a step of ∠15°. The present results are in good agreement with some recent experimental data.