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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 IREN complex for neutron physics research was constructed at the Frank Laboratory of Neutron Physics based on a linear accelerator of electrons up to an energy of 50 MeV. Measurements of the neutron flux density in a wide range of energies (from thermal to fast) are required in various experiments. This is done by neutron activation analysis with high-resolution gamma spectroscopy. In order to determine the flux of resonant neutrons more accurately, one needs to calculate the effective resonance integrals with specific features of the real neutron spectrum and the thermal motion and absorption of neutrons in the sample taken into account. A program for computation of effective resonance integrals has been developed for this purpose. The effective resonance integrals for 197Au, 95Zr, 97Zr, and 63Cu are calculated using this program. The values differ considerably from the ones given in reference literature. These results are used to more accurately determine the flux density of neutrons.

The first experiments were carried out to study the elemental composition of archaeological ceramics using prompt gamma activation analysis (PGAA) at the pulsed reactor IBR-2, Frank Laboratory of Neutron Physics (FLNP) - Joint Institute for Nuclear Research (JINR). A radiation-resistant n-type High Purity Germanium (HPGe) detector was used to measure the radioactivity. The concentrations of 14 elements were determined namely; Al, C, Ca, Fe, Gd, H, K, Mn, Na, P, S, Si, Sm, and Ti. The obtained results were compared with those analyzed by other analytical techniques INAA (Instrumental Neutron Activation Analysis) and portable X-ray fluorescence (XRF) for the same archaeological batches. The results revealed a good agreement within a range of 1-30%. These insights will contribute to the discussion of improving the PGAA installation and automation of the data obtained, which in turn will improve the quality of analysis and increase the number of determined elements. In this work results are presented, and the analytical merits are compared.

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.

A series of experiments has been conducted at the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR) in order to study the possibility of determining the moisture content of coke using a standard neutron source. The proposed method is based on a measurement of the spectrum of prompt γ rays emitted when samples are irradiated by fast and/or thermal neutrons. The moisture content is determined from the area of the peaks of characteristic γ rays produced in the radiative capture of thermal neutrons by the proton (Eγ = 2.223 MeV) and inelastic scattering of fast neutrons by 16O (Eγ = 6.109 MeV). The 239Pu–Be neutron source (〈E n 〉 ~ 4.5 MeV) with an intensity of ~5 × 106 n/s was used to irradiate the samples under study. A scintillation detector based on a BGO crystal was used to register the characteristic γ radiation from the inelastic fast neutron scattering and slow (thermal) neutron capture. This paper presents the results of humidity measurement in the range of 2–50% [1, 2].

A neutron activation analysis (NAA) of three samples of human remains of the 16th and 17th centuries from the necropolises of the Moscow Kremlin has been carried out at FLNP JINR. The samples were irradiated at two facilities: the IREN source of resonance neutrons and the IBR-2 reactor. Spectra of the induced activity of the irradiated samples were measured by using the automatic measurement system developed at the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR). This system consists of a high-purity germanium detector with spectrometric electronics, a sample changer, and control software. Mass fraction of arsenic, mercury, and some other elements were calculated using two NAA methods—relative and absolute. The obtained values confirm the fact of acute mercury poisoning of Anastasia Romanovna, the first wife of Tsar Ivan Vasil’evich the Terrible, the first Russian Tsarina (died in 1560). High levels of mercury were detected in the bone remains of Tsarevich Ivan Ivanovich (died in 1581), the son of Tsar Ivan the Terrible, and Prince Mikhail Vasil’evich Skopin-Shuiskii (died in 1610). The results provide an opportunity to introduce into scientific circulation the exact values of mass fraction of mercury, arsenic, and other elements in the samples taken from the burials of the Russian historical figures of the second half of 16th–early 17th century.