A study of irradiation-induced creep and re-sintering of large grain sized fuel of the VVER type was carried out using the developed procedures and experimental facilities under radiation with fission rates of 1.0 × 10¹³ and 1.2 × 10¹³ 1/(cm³ s). Strain diagrams generated during creep studies within the strain range of 10−40 MPa were obtained at effective sample temperatures of 943, 1020, 1200 and 1301 K. It was demonstrated that strain is mainly determined by irradiation induced creep within the temperature range of up to 1123 K. This was confirmed by its linear dependency on stress. At higher temperatures, the effect of radiation-thermal creep grows, and its contribution to the total strain increases with the growth of stress. Creep rate values obtained at temperatures of 1200 and 1301 K are higher than those of uranium dioxide with standard grain size. Strain diagram produced during the studies of re-sintering of an 88.32 mm high fuel column was obtained at the effective specimen temperature of 960 K. In terms of height, re-sintering amounted to 0.070−0.095%. It was showed that, within the limits of the experimental error, irradiation-induced re-sintering makes a small contribution to the resulting strain of the fuel in comparison with creep.

New algorithms to operate with new analog spectrometer of the DGFRS-2 installed at DC-280 cyclotron setup are presented. The main goal of application of these algorithms is to search an optimal time correlation recoil-alpha parameter directly during the acquisition C++ code execution. A new real-time flexible algorithm is presented in addition to the conventional ER-α one which is in use for a few years at the DGFRS-1 setup installed at the U-400 FLNR cyclotron. Note that the spectrometer operates together with the 48 × 128 strip DSSD (Double Side Strip Detector; 48 × 226 mm² ) detector and low pressure pentanefilled gaseous detector (1.2 Torr; 80 × 230 mm² ) are presented schematically. First beam test results in ⁴⁸Ca induced nuclear reactions are presented too.

The technology of forming a cryogenic deuterium uniform in thickness layer in a shell located in an experimental box is described. The obtained cryogenic deuterium layers are presented, which meet the requirements of the uniform in thickness of the cryogenic target layer.

The Monte Carlo method was used in a 2D model of layered HTSC to explore the dynamics of a vortex lattice in the presence of a nonuniform temperature field. Vortex configurations in a superconductor with a “thermal spot” have been found. The characteristic size of the region in which melting of the vortex lattice is observed is shown to exceed the characteristic size of the thermal spot. The possibility of directional movement of vortices by means of a temperature gradient is demonstrated in a numerical calculation.

We have considered the possibility of using a neural network for calculation the weight coefficients corresponding to the Bragg curves for forming a uniform depth dose distribution in proton therapy.

The problem of beam dynamics optimization in linear accelerator is reduced to finding the global minimum of the quality functional in multidimensional parameter space. To solve the problem, the genetic stochastic algorithm is used, based on modeling a multivariate normal distribution with adaptation of the covariance matrix, while the calculation of the matrix is not required. The modification of the algorithm is population mutation, which allows to provide a sufficient number of samples both near the “best” point and at a distance from it and to avoid the rapid contraction of the sample to the local extremum point. The application of this method to particle dynamics optimization problem provided a significant improvement of beam characteristics.

The previously developed improved photoemission model has been applied to a detailed analysis of the process of high-brightness electron bunch formation process in the RF photogun. Space charge-dominated photoemission has a significant influence on the formation of transverse emittance as well as on the energy distribution within the emitted electron bunch.

A new experiment to measure electric dipole moments (EDMs) of elementary particles, based on measuring the polarized beam’s spin precession frequency, has been proposed for implementation at the NICA facility (JINR, Russia). Polarized beam experiments in general require long spin-coherence times at around 1000 seconds. The proposed method involves a further complication (enhancing the measurement precision by several orders of magnitude): a switching of the accelerator guide-field polarity as part of its CW−CCW injection procedure. For the realization of this latter procedure a calibration process is necessary, during which the beam polarization axis changes its orientation from the radial (used for the measurement) into the vertical (used for the calibration) direction. In case this change occurs adiabatically, the beam particles’ spin-vectors follow the direction of the polarization axis, which negatively affects the calibration accuracy; however, the violation of the adiabiticity condition raises the question as to the conservation of the beam’s spin-coherence. We address this question in the present investigation.

The article presents mathematical models for predicting the reliability of the service personnel in a normal and stressful environment. The probabilistic models of making critical and non-critical errors by the personnel at the moment of time t are considered. A model is presented that analyzes the probability of a system failure due to the fault of the maintenance personnel.

Cross section of neutrino absorption by selenium-82 nuclei is calculated. The neutrino flux is produced the artificial neutrino sources ³⁷Ar, ⁵¹Cr and ⁶⁵Zn. The experimental data on charge-exchange reaction ⁸²Se(³ He,t)⁸²Br are used in calculations. It is shown, that ⁸²Se is a perspective isotope for calibration experiments aimed at new types of neutrino searches.

A method is proposed for restoring the neutron field created by a vacuum accelerating tube with a metal-tritium target of complex configuration. The method uses data from neutron measurements on a disassembling vacuum bench with a small deuterium target. The method ensures radiation safety of work. Specific examples of its application in the process of studying ion diodes developed at the National Research Nuclear University MEPhI are given.

In the case of acceleration of particles with a charge-to-mass ratio of 1 : 2, the length of the cavity is practically doubled compared to a proton accelerator for the same energy. At an output energy exceeding 1.0 MeV per nucleon, the cavity length becomes large L_cav ≈ 3 λ, where λ is the wavelength of the TE211 working mode, which leads to a critically small frequency separation between the working TE211 quadrupole mode and the TE11n dipole modes. For mode separation, it is proposed to use coupling windows between neighboring cavity segments, which in turn change the field distribution along the cavity. Uniformity is restored with the help of plungers located along the cavity in each of the 4 segments. The result of the work is the calculation of the RFQ accelerating cavity with the following main parameters: ion type – deuterons or He⁺⁺, operating frequency 202 MHz, injection energy 75 keV, length 4.3 m, pulse power not more than 300 kW, energy of accelerated ions 1.25 MeV/nucleon, pulse current of deuterons 50 mA and He⁺⁺ 10 mA. Based on the performed electrodynamic and beam dynamics calculations, the RFQ cavity was designed.

This article describes the development of an ion beam extraction and formation system with longitudinal travel of the electrode system with respect to the plasma electrode for a 2.46 GHz ECR source. Optimization of the electrode extracting system and focusing electrostatic lens have been performed. The dynamics of the He²⁺ proton and ion beams in the source have been simulated.

Within the framework of the BELA (Based on the ECR ion source Linear Accelerator) project, designed to solve various problems, an injection complex based on several ion sources is being created. One of the tasks is multi-beam irradiation of structural materials of nuclear and thermonuclear power plants to analyze their radiation resistance. Heavy (Fe) and light (H/He) ion beams will irradiate the target in the same chamber simultaneously. To generate beams of light ions, a compact ion source based on electron cyclotron resonance (ECR source) is being developed. This paper contains a description of the design of the ECR, that is, the source of light ions and preliminary results on the generation of a helium ion beam.

The resource of nuclear facilities is largely limited by the degradation of structural or functional materials. Under the action of high-energy neutrons, defects in the crystal lattice appear in the material and the accumulation of transmutation products (helium and hydrogen) occurs in the structure of the material. Qualification of structural materials using reactor irradiation takes several years, and the samples of materials themselves become activated, which makes subsequent post-reactor tests difficult. Simulation experiments on a beam of heavy ions making it possible to analyze the radiation resistance of structural materials of nuclear and fusion reactors have been carried out at the Kurchatov Complex of Theoretical and Experimental Physics (National Research Center Kurchatov Institute) since 2009. Simulation experiments at an accelerator make it possible to carry out high-dose tests in no more than a few days with control over the conditions of the irradiation (temperature of target samples, ion flux, radiation dose). The paper presents a description of the simulation irradiations carried out at the HIPr heavy ion accelerator.

The LEBT channel is defigned for transporting beams of multiply charged ions with A/Z from 4 to 8 (up to ²⁰⁹Bi²⁷⁺) from a laser source of heavy ions and 70 kV extractor system to the initial part of the linear accelerator. The LEBT consists of: the transport line for separation of the main ion beam, and the section for beam matching with the accelerating section RFQ. Beam dynamic simulation was carried out taking into account fields three-dimensional distributions of the magnetic elements. As a result of the simulation of particle dynamics, it was possible to provide the 4-dimensional matching of ²⁰⁹Bi²⁷⁺ with the RFQ, with a minimum emittance increasing in the LEBT.

We search for the ways to improve the lattice implementation of the extended Hubbard model in order to compute quantum mechanical operators of increased complexity. The standard method does not allow to eliminate all the divergences in observables, which prevents obtaining a stable distribution over configurations in the Monte Carlo method. In a set of calculations, the positive effect of two approaches is demonstrated: an introduction of additional Hubbard fields and a selection of the Hubbard−Stratonovich transformation’s parametrization.