Project of the source of relativistic electrons with angular momentum
Development of the source of relativistic "vortex" electrons (with orbital angular momentum) based on the LINAC-200 electron accelerator complex is started in JINR. First stage of this project is the testbench with the electron energy of 5 MeV for the RF-gun based option and of 400 keV for the DC-gun based one. Testbench...
One of the important parameters characterizing the interaction of electron beams with matter is the deep dose distribution. To develop a new approach for shaping electron beams using specially created materials suitable for the manufacture of complex 3D-printed devices, it is necessary to analyze the features of ionizing radiation propagation.
In this work, numerical simulations and...
Nowadays, high-energy radiation sources are increasingly used in nondestructive X-ray inspection. The main reason for the growing popularity of gamma radiation sources with electron energies of more than 1 MeV is the possibility of their application in high-energy radiographic control with innovative digital systems. Such systems have the advantages of high penetration, high sensitivity of...
The use of a temperature gradient in the study of the dynamical diffraction of a spherical X-ray wave in the Laue geometry is due to the fact that the atomic reflecting planes in the crystal are fan-shaped, which makes it possible to control the focusing process. It was shown in [1] that in the case of a short period superlattice a smooth change in the gradient value can focus different...
Experimental results of a study of the properties of microfocus bremsstrahlung (Bs) generated in narrow inner silicon (Si) and tantalum (Ta) targets of a betatron with an electron energy of 18 MeV are presented. The targets were Si crystals 50 and 8 ยตm thick and Ta foil 13 ยตm thick oriented with a goniometer along the direction of the inner electron beam. The results showed a strong dependence...
Modern radiofrequency (RF) photoinjectors that are widely spread as $e^-$ sources for free-electron lasers, colliders and synchrotron radiation facilities, use semiconductor photocathodes quite often. Such photocathodes, as a rule, consist of a semiconductor layer (units-tens of $\text{nm}$) with a high QE and a metal substrate. The use of such structures is associated with a number of...
Improved thermal barrier coatings (TBCs) will enable future gas turbines to operate at higher gas temperatures. Considerable effort is being invested, in identifying new materials with even better performance than the current industry standard, yttrium stabilized zirconia (YSZ). TBCs are also supposed to be applied in spacecrafts as protective layer against heat. The operation of spacecrafts...
This study explores the application of catastrophe theory to describe the molecular mechanism of smectisation and the regulation of polymorphism in nematic liquid crystal (NLC) systems that are based on polar liquid crystals, whose molecules have a large dipole moment directed along the long axis of the moยฌยฌleยฌcule .We have identified a relationship between the control variables of cusp...
The purpose of this work is to obtain a dynamic picture of the interaction of two solitons by analyzing the solution of the KdV (Korteweg de Wriz) equation. By changing the variables in the exact solution of the KdV equation, a solution is obtained that can be used to visualize the internal mechanism of the interaction of two solitons. At the corresponding boundary transitions in the...
The possibility of the photonuclear production of radioisotope 111In is discussed. The 111In radionuclide is among those that are used most frequently in diagnostics since it is a short lived (T1/2 = 2.8 day) gamma emitter (Eฮณ = 171.3, 245.4 keV). Moreover, this radioisotope is used in Auger therapy.
Enriched tin targets 112Sn were irradiated at the linear electron accelerator of Alikhanian...
Three-dimensional printing has a wide range of applications in science and technology. Fused filament fabrication (FFF) is a commonly used 3D printing technology, which is now being increasingly employed in radiation physics. In FFF, the internal structure of an object is primarily determined by its fill pattern and selected print modes. Therefore, this study aims to examine the interaction...
This research on the transverse profile of ionizing radiation beams and the development of a multi-angle beam scanning detection system is highly significant and applicable in various fields.
In technological and research applications, it is crucial to accurately determine the transverse profile of ionizing radiation beams for effective quality control purposes. However, most existing...
As part of the commissioning work at the linear electron accelerator LINAC-200 (JINR), we conducted experiments to study the characteristics of a pulsed neutron source obtained by irradiating a converter target with a 140 MeV electron beam. We performed numerical simulations to estimate the parameters of the neutron source and the energy spectra of neutrons in lead and tungsten targets of...
In the process of irradiation of materials by fluxes of heavy particles (protons, neutrons, alpha particles) damage of material structure is observed. As a result of accumulation of such damages, there is a subsequent change in the properties of materials, in particular, its embrittlement and hardening. In this work, to observe the effect of heavy irradiation particles on the mechanical...
Abstract: Many properties of corundum, including the radiation and thermal resistance, large forbidden zone, high light output, and spectral and temporal characteristics, make it an attractive converter for UV and particle detectors.
We have at our disposal many corundum crystals of different thicknesses with various activators, which were studied in the UV range of the spectrum....
Cross sections of proton-induced reactions on tin up to energies of 18 MeV using the stacked-foil activation technique have been measured. Experimental values for 114Sn(p,ฮฑ)111In, 114Sn(p,pn)113Sn, 114Sn(p,2n)113Sb, 120Sn(p,n)120m,gSb, 120Sn(p,ฮฑ)117m,gIn reactions cross-sections are reported.
A stack of enriched 114Sn and 120Sn foils was irradiated using 18 MeV proton beam provided by...
Abstract: The article deals with the construction of a single-channel light rangefinder. At the same time, one of the main difficulties is the presence of depolarization of light, which forms residual light at the output of the analyzer, which greatly affects the measurement accuracy. It is shown that in order to exclude residual light by compensating for depolarization, a KDP crystal plate...
To operate a high-precision light rangefinder in a wide temperature range (-10 +40) ยฐ C, as well as to resolve the ambiguity of the measurement, it is necessary to ensure a change in the resonant frequency within 10-15% of the fundamental frequency. At a fixed modulation frequency of 1200 MHz, a device for smoothly changing the modem frequency within 150-180 MHz should be install on the modem...
Linear rare earth permanent magnet (REPM) structures of split-pole type with harmonic distribution of magnetization for generators of synchrotron radiation are considered. The main attention is paid to issues of high order harmonic amplitude decrease at longitudinal Fourier-expansion of the field along the electron beam axis. Itโs presented by a comparison that relative oberton amplitudes...
Accelerators of charged particles are powerful experimental tools, which are used in many fundamental researches and applied tasks. Compact accelerators are currently widely used for pretesting and proof-of-principle experiments for MegaScience projects, as well as for applied purposes. In this work, we present the detailed technical report of Microtron Experimental Facility at Tomsk...
Cherenkov radiation is widely used effect, which finds a broad application in the charged particle beam diagnostics. Corundum crystals are prospective radiators for obtaining Cherenkov light. Corundum radiators may significantly change their optical properties during extensive exploitation with particle beams that would influence Cherenkov light intensity. In this report, we experimentally...
The Fraunhofer diffraction of an electromagnetic wave by a slit on an opaque screen located between vacuum and an anisotropic material medium is considered. Two cases of anisotropic media are considered and compared: with a closed wave vector surface (CWVS) and with an open wave vector surface (OWVS).
Formulas that describe diffraction in these two types of anisotropic media are obtained....
In recent years studies have shown that doping a crystal with amino acids improves the non-linear optical properties of ฮฑ-LiIO3crystal [1, 2]. The authors[3] have studied the interaction of lithium with iodic acid and have shown that, at compositions close to 0.2โคxโคO.34, 2LiIO3โขHIO3crystals are formed in a mixture of Li1-xHxIO3.
The present work deals with the synthesis, IR spectrum, thermal,...
The results of a study of deposition by a new type of magnetron developed by us - an acoustoplasmic low-frequency magnetron, are presented. The deposition of conductive and non-conductive materials is considered, and also polycrystalline and porous structures.
Short-period, high-field undulators are widely used on modern SR sources to generate high-intensity coherent radiation. In order to achieve the stability of the properties and the quality of the radiation received in undulators magnetic field of ID has to meet very tough tolerances, which depend on the accuracy of the arrangement of magnets in the assembly. Such tolerances can be achieved by...
Synchrotron sources play an essential role in contemporary scientific investigations in physics, chemistry, biology, materials science, and other fields. They offer high intensity, a wide energy spectrum, and distinct synchrotron radiation characteristics, making them unmatched for a variety of experimental objectives. Recent years have witnessed substantial endeavors in advancing...
Hall magnetometry is one of the basic measurement methods for research and diagnostics of undulator systems for generating coherent synchrotron radiation. Present work is devoted to the development of 3D measurement device based on Hall sensors for the studies of magnetic characteristics of undulator systems constructed of permanent magnets. The main purposes of the developed 3D magnetic...
The study of light scattering in school textbooks did not consider the heterogeneity of the crystal, and Maliusโs law was written for the ideal crystal. In this paper, I consider it expedient to discuss the mentioned issues in some detail. Given the heterogeneity of the crystal, the general or probabilistic form of Maliusโs law is proposed.
Consider the inhomogeneity or ellipticity of the...
The effect of p-nitroaniline on a model of biological membranes consisting of the sodium salt of di-(2-ethylhexyl) sulfosuccinic acid-n-heptane and water was studied by X-ray analysis.
Structural changes, phase transformations, changes in the degree of compactness of the liquid crystal structure, thereby changing the conditions of transport phenomena through model membranes, have...
In a huge number of works on the synthesis of high-temperature superconductors (HTSCs), two main directions are distinguished: works on the synthesis of new superconductors ([1] -as well as references therein), and works on the development of new methods for improving the physical parameters of traditional HTSC materials [2โ4].
In this paper, we consider three methods for the synthesis of...
The possibility of acceleration of charged particles in a low-pressure acoustoplasma at low values of the voltage applied to the plasma has been shown theoretically and experimentally. In experiments in neon acoustoplasma, the average gradient of the external voltage applied to the anode-cathode gap was < 5 V/cm.
Structural rearrangements of di-(2-ethylhexyl)sulfosuccinic acid (AOT) - n-heptane-water liquid-crystal system simulating biological membranes, under the influence of different concentrations of Dimethyl sulfoxide (DMSO).
It has been established that the influence of Dimethyl sulfoxide (DMSO), by changing the degree of hydration of the polar core, changes the characteristic parameters of the...
