[en] The effect of the acceleration of a nucleus on the neutron states is studied in the frame of the independent-particle nuclear shell model. For this we solve numerically the time-dependent Schrödinger equation, with a moving mean-field of Woods-Saxon type. The time evolution of a neutron states at the Fermi level is calculated for ²³⁶U and acceleration parameter A=0.5 (in 10⁴⁴ [fm/sec²]). It is roughly the acceleration during the Coulomb repulsion of two ²³⁶U nuclei when they are 20 fm apart. We keep this acceleration constant for 10⁻²¹ sec before we switch it off (A=0) and follow the wave packet for another 10⁻²¹ sec. During the acceleration, the wave function oscillates with increasing amplitude until it escapes, mainly in the direction opposite to the motion of the nucleus. The mean value of its energy (in the nuclear system) increases from -4.80 MeV to -3.15 MeV and 12% of the wave packet leave the nucleus. During the uniform motion, the wave packet continues to oscillate and to escape at a lower rate: an extra 2%. We repeated the calculations for two neighbouring states and found the emission rate to depend strongly on the position of the neutron state with respect to the Fermi energy. Finally, the effect of the nuclear deformation on the acceleration induced neutron emission is studied. In this case the period of oscillation is larger and the amplitude smaller. The angular distribution with respect to the direction of motion is also different: it has, in the nuclear system, an intense component almost perpendicular to the deformation axis.

[en] In our previous publications we discussed different manifestations of a new decay channel of the low excited heavy nuclei called collinear cluster tri-partition (CCT). The most populated CCT mode was revealed in the mass correlation distribution of fission fragments (FFs) as a local region ('bump') of increased yields below the loci linked to the conventional binary fission. The bump was dubbed the 'Ni-bump' because it is centered at the masses associated with the magic isotopes of Ni. The bulk of the results has been obtained by using the 'missing mass' approach. It means that two decay products (fragments) are detected in coincidence using a double armed time-of-flight spectrometer, while the significant difference between their total mass M_S = M₁ + M₂ and the mass of a mother system serves as a sign of at least ternary decay. Mainly a scattering of fragments at the entrance of an E-detector gives background events simulating ternary decay. Observation of the specific linear structures in the M₁ –M₂ distributions (mass correlation plots) served as a criterion for a sufficient suppression of the background. Analysis of the fission events from the 'Ni-bump' allowed us to draw a conclusion that the ternary fission observed should be treated as 'almost sequential', but it is very close to the sequential one. Here we present our new experimental result that decisively confirms this conclusion.

[en] In the frame of TANGRA-project at JINR-FLNP (Dubna) we measured the gamma-rays resulting from the inelastic scattering of 14.1 MeV neutrons on magnesium. As a source of neutrons we used ING-27 portable neutron generator of VNIIA (Moscow) where the neutrons are produced in a d-t fusion-fission nuclear reaction, ³H(d,n)⁴He. The α-particles were registered by a 64-pixel Si charge particle detector embedded in ING-27 vacuum chamber. The sample tested was a 10cm-thick plastic cube filled with MgO powder. The gamma-rays from the interaction of neutrons with the sample we registered by a Romashka-type Fe-protected array, consisted of 22 hexagonal NaI(Tl) scintillator prisms. The analog signals form all the α- and γ-detectors were collected in list-mode, simultaneously, by a computerized 32-channel data acquisition system (DAQ) from JINR AFI-electronics, which was used, also, for digitizing and storing the waveforms on the computer hard-drive for further off-line analysis with CERN-ROOT modular scientific software toolkit. Using the time-correlated associated particle method (TCAPM), also known as tagged neutron method (TNM), the influence of the background radiation on the collected gamma-ray spectra was drastic reduced. We obtained the angular distribution of 1.368 MeV gamma-rays from ²⁴Mg(n, n'γ-)-reaction in the range from ~15° to ~165° with a good statistical accuracy. Here we report the results from our first experiment in comparison with the available data from the other authors. Further experiments are foreseen.

[en] Modification of software systems for automation of experiments requires time comparable to their development due to uniqueness. In this regard, methods and means that reduce these terms are relevant. The paper presents a set of tools designed to build distributed software systems for automation of experiments (SAE). Service-oriented architecture is used. The main means of the complex are multi-user programs. Each SAE, built by means of the complex TySSA, consists of independent components (programs in the format .exe). If the necessary services are available, their integration into the experiment automation system corresponding to the planned experiment technique is performed by the experimenter and requires 10-20 minutes. The complex TySSA is designed for use in experiments at the IBR-2 research reactor, but can be used in other problem areas.

[en] Prostatitis is the most common urologic disease in adult males younger than 50 years and the third most common urologic diagnosis in males older than 50 years. Chronic prostatitis (CP) is functional, somatoform disorder with a high worldwide prevalence estimated in systematic reviews or population studies at 10-32%. However, CP is a more common condition, with 35-50% of men reported to be affected by symptoms suggesting prostatitis during their lifetime. Benign prostatic hyperplasia (BPH) is an internationally important health problem of the man, particularly in developed countries, and represents the most common urologic disease among of men after the age of fifty. Incidence of histological BPH could be over 70% at 60 years old and over 90% at 70 years old. To date, we still have no precise knowledge of the biochemical, cellular and molecular processes underlying the pathogenesis of BPH. Although the influence of androgens and estrogens has been demonstrated, hormonal factors alone may not fully explain BPH development. Thus, both BPH and CP is the very common urologic disease in adult males. Moreover, use systematic review methods provide the statistical evidence that the association between BPH and CP is significant. Prostatitis, as well as BPH, can be a cause of an elevated prostate specific antigen (PSA) level in blood. This warrants the need of reliable diagnostic tool which has ability not only to diagnose CP reliably but also to differentiate it from the BPH. It was reported that the risk of having BPH and CP depends on lifestyle and diet, including the intake of Zn and some other trace elements (TE). TE have essential physiological functions such as maintenance and regulation of cell function, gene regulation, activation or inhibition of enzymatic reactions, and regulation of membrane function. They can play the significant role in the oxidative stress. Essential or toxic (mutagenic, carcinogenic) properties of TE depend on tissue-specific need or tolerance, respectively. Excessive accumulation or an imbalance of the TE may disturb the cell functions and may result in cellular degeneration or death. In our previous studies a significant involvement of Zn and some TE in the function of prostate was observed. Moreover, it was found that intracellular Zn and Ca excess is one of the main factors in the etiology of BPH. One of the main functions of prostate gland is a production of prostatic fluid with extremely high concentration of Zn and some other chemical elements. The first finding of remarkable high level of Zn concentration in human expressed prostatic fluid (EPF) was reported in the beginning of 1960s. Analyzing EPF expressed from prostate of 8 apparently healthy men aged 25-55 years it was found that Zn concentration varied in range from 300 to 730 mg/L. After this finding several investigators have suggested that the measurement of Zn level in EPF may be useful as a marker of prostate secretory function. It promoted a more detailed study of Zn concentration in EPF of healthy subjects and in those with different prostate diseases, including BPH and CP. A detailed review of these studies, reflecting the contradictions within accumulated data, was given in our earlier publication. In present study it was supposed by us that apart from Zn the levels of some other TE in EPF have to reflect a difference between functional changes of chronic inflamed prostate and hyperplastic prostate. Thus, this work had four aims. The first one was to present the design of the method and apparatus for micro analysis of Br, Fe, Rb, Sr, and Zn in the EPF samples using energy dispersive X-ray fluorescence (EDXRF) with radionuclide source ¹⁰⁹Cd. The second aim was to assess the Br, Fe, Rb, Sr, and Zn concentration in the EPF samples received from patients with CP and BPH. The third aim was to evaluate the quality of obtained results and to compare obtained results with published data. The last aim was to compare the concentration of Br, Fe, Rb, Sr, and Zn in EPF samples of chronic inflamed and hyperplastic prostate. All studies were approved by the Ethical Committee of the Medical Radiological Research Center, Obninsk.

[en] Analysis of existing database on the relative abundances of delayed neutrons and half-lives of their precursors measured for neutron induced fission of heavy nuclei in the energy range above 14 MeV shows that such data are not available for many nuclides which are important for nuclear fuel cycle. In the present work for the first time the time dependence of delayed neutron activity for the neutron-induced fission of ²³⁶U in the energy range from 14.2 to 18 MeV is covered.

[en] The investigation of the ROT effect for the fissioning nuclei in the process has been continued at the FRM-II Munich reactor (Germany). The experiment with²³⁵Utarget was performed at a polarized monochromatic neutron beam with an energy of 60 MeV provided by the POLI instrument, in order to figure out the dependence of the effect on the incident neutron energy. Up to now all measurements of the ROT effect were performed for the cold neutron induced fission, where several fission channels are mixed with unknown weights. The correlation coefficient for 60 MeV neutrons was found to be A_γ = (1.25±0.31)·10^-4, which is compared with the corresponding values for ²³⁵U, obtained with the cold neutrons: Aγ = (1.66±0.16)·10^-4 (by the ITEP group).

[en] Molybdenum nucleus has many natural and artificial isotopes important for fundamental and applicative researches. Cross sections, angular correlations and isomer ratios in fast neutrons induced reactions up to 25-30 MeV were evaluated using codes realized by authors as well as dedicated software. Contributions of different nuclear reaction mechanisms in the cross sections were also determined. Parameters of nuclear optical potential, density levels and radius channels were extracted. Theoretical evaluations were compared with existing experimental data. The results of present work were realized in the frame of the fast neutrons scientific program at FLNP basic facilities (IREN and EG5) and are necessary for future experiment preparation.

[en] Earlier we discussed the manifestations of a new original effect appeared at the crossing of metal foils by fission fragments (FF). A significant mass deficit in the total mass M_sum of the fission fragments detected in coincidence with ions knocked out from the foil was observed. It has been shown that at large angles of scattering of the knocked-out ions, predominantly conventional elastic Rutherford scattering occurs at energies below the Coulomb barrier. As a result, M_sum corresponds to the mean mass of the mother system after emission of fission neutrons (no missing mass). In contrast, in near frontal impacts, the fission fragment misses essential part of its mass; and the bulk of the brake-up residuals show the magic nucleon compositions. Here we present one of the new results, obtained using thick carbon foil as a degrader.

[en] Machine learning is one of the popular methods for analyzing and processing complex data. Despite it shown good accuracy, applying it in the scientific field is hindered by the unpredictable neural networks behavior. Thus, incorrect results can be caused by applying neural networks to separate particles in scintillator. Therefore, it was necessary to compare series of different neural networks architectures and to find out the feasibility of their application to the task of separating particles according to the shape of the pulse.