Showing papers in "Radiophysics and Quantum Electronics in 2018"
TL;DR: In this article, the authors considered a cross-polarization optical coherence tomography system with a common path for the sounding and reference waves and active maintenance of the circular polarization of a sounding wave.
Abstract: We consider a cross-polarization optical coherence tomography system with a common path for the sounding and reference waves and active maintenance of the circular polarization of a sounding wave. The system is based on the formation of birefringent characteristics of the total optical path, which are equivalent to a quarter-wave plate with a 45° orientation of its optical axes with respect to the linearly polarized reference wave. Conditions under which any light-polarization state can be obtained using a two-element phase controller are obtained. The dependence of the local cross-scattering coefficient of light in a model medium and biological tissue on the sounding-wave polarization state is demonstrated. The necessity of active maintenance of the circular polarization of a sounding wave in this common path system (including a flexible probe) is shown to realize uniform optimal conditions for cross-polarization studies of biological tissue.
43 citations
TL;DR: In this article, an effective method for reducing nonequidistance when recording the spectral components of an interference signal in ultra-wideband spectral-domain optical coherence tomography was developed.
Abstract: We develop an effective method for reducing nonequidistance when recording the spectral components of an interference signal in ultra-wideband spectral-domain optical coherence tomography. For this purpose, a corrector consisting of two identical prisms is used in a diffraction-grating spectrometer. The corrector rotation with respect to the diffraction-grating plane and a variation in the angle between the corrector elements allow one to adjust the equidistant spatial distribution of the spectral components in the photoreceiver array. It is shown experimentally that the developed method substitutes digital correction and leads to a significant reduction of the computational load in the optical coherence tomography device.
17 citations
TL;DR: In this paper, the resonant interaction of relativistic electrons with ion-cyclotron waves in the Earth radiation belts was analyzed on the basis of solving numerically a system of equations of particle motion along with the efficiency of this interaction for a single pass of the particle through the wave packet.
Abstract: We analyze the resonant interaction of relativistic electrons with ion-cyclotron waves in the Earth radiation belts. Finite-length wave packets with variable frequencies and different amplitude profiles are considered. Specific features of the nonlinear interaction regimes are analyzed on the basis of solving numerically a system of equations of the particle motion along with the efficiency of this interaction for a single pass of the particle through the wave packet. In the first part of this work, the peculiarities of the trajectories of individual particles are analyzed. The influence of the shape of the wave packet on the well-known regimes, such as particle trapping by the wave field and particle phase bunching, which leads to a non-zero average variation in the pitch angle in an inhomogeneous medium, are considered. It is shown that a long stay of a particle near the separatrix on the phase plane in the region far from the saddle leads to a strong decrease in the pitch angle of the particle in the absence of the trapping as well. This nonlinear regime (directed scattering) is possible for comparatively low initial pitch angles. In this case, the value of the pitch angle decrease depends on the initial phase of the particle. It is shown that the trajectories corresponding to the directed scattering can be regarded as a transitional type of trajectories, between the trajectories of the untrapped and trapped particles. Quantitative estimates of variations in the pitch angle are obtained, and it is confirmed that the directed scattering and trapping of particles by the wave field can lead to electron precipitation into the loss cone.
16 citations
TL;DR: In this paper, a method for the analysis of groups of unidirectional waves on the surface of deep water, which is based on spectral data of the scattering problem in the approximation of a nonlinear Schrodinger equation, is proposed.
Abstract: We propose a method for the analysis of groups of unidirectional waves on the surface of deep water, which is based on spectral data of the scattering problem in the approximation of a nonlinear Schrodinger equation. The main attention is paid to the robustness and accuracy of the numerically obtained spectral data. Various methods of choosing the wave number of the carrier wave, which rely on the analysis of the local Fourier transform and the zero-crossing wave analysis, are considered. The most robust wave numbers have been chosen on the basis of two model examples. A method for improving the accuracy of the soliton amplitude prediction, which uses the “feedback” in solving the associated scattering problem, is proposed. In the wave steepness range from 0.15 to 0.30, the accuracy of determining the amplitude of the soliton group by this technique lies in a range of 10%.
13 citations
TL;DR: In this paper, the spatial distribution of excited oxygen atoms in the HF-pumped ionospheric region based on two-station records of artificial airglow in the red line (λ = 630 nm).
Abstract: We describe the method and the results of modeling and retrieval of the spatial distribution of excited oxygen atoms in the HF-pumped ionospheric region based on two-station records of artificial airglow in the red line (λ = 630 nm). The HF ionospheric pumping was provided by the Sura facility. The red-line records of the night-sky portraits were obtained at two reception points—directly at the heating facility and 170 km east of it. The results were compared with the vertical ionospheric sounding data. It was found that in the course of the experiments the airglow region was about 250 km high and did not depend on the altitude of the pump-wave resonance. The characteristic size of the region was 35 km, and the shape of the distribution isosurfaces was well described by oblique spheroids or a drop-shaped form. The average value of the maximum concentration of excited atoms during the experiment was about 1000 cm−3.
13 citations
TL;DR: In this paper, the authors studied the dynamics of the two-soliton interaction within the framework of a completely integrable model, namely, the Gardner equation with negative cubic nonlinearity, which admits the existence of a limiting soliton.
Abstract: We study the dynamics of the two-soliton interaction within the framework of a completely integrable model, namely, the Gardner equation with negative cubic nonlinearity, which admits the existence of a limiting soliton. The features of the soliton interaction with participation of a thick soliton are demonstrated. Special attention is paid to the nonlinear-interaction influence on the wave-field moments, which determine the skewness and the kurtosis in the theory of turbulence.
11 citations
TL;DR: In this paper, the authors developed the numerical method of moments for solving an integral equation that describes the distribution of the charge along a thin finite-length antenna wire in an anisotropic medium in the quasistatic approximation.
Abstract: We develop the numerical method of moments for solving an integral equation that describes the distribution of the charge along a thin finite-length antenna wire in an anisotropic medium in the quasistatic approximation. It is shown that the method of moments can be used to calculate the electrodynamic characteristics of such an antenna under the conditions where the kernel of the integral equation has a singularity related to the resonance cone. The influence of the ratio between the elements of the dielectric permittivity tensor and the method of partitioning of the antenna surface on the calculation accuracy is analyzed. It is shown that the relative error of calculations of the antenna characteristics is a fairly small value of about 1% if the antenna wire is divided into ten segments.
9 citations
TL;DR: A new combined decision statistic with the characteristics that are close to those of the exact decision statistic is introduced for a wide signal-to-noise ratio range.
Abstract: We present a detailed study of the characteristics of the exact decision statistic for the optimal incoherent signal detection in a multielement antenna array. The exact decision statistic is derived from a rigorous expression for the likelihood ratio in the case where the useful-signal amplitudes at the antenna-array elements are identical, whereas the phases are random. The analysis is carried out in the space of the variables which are observed at the outputs of the incoherent matched filters performing the initial signal processing at each antenna-array element. Variation in the signal-to-noise ratio is shown to deform the boundary of partitioning of the multidimensional observation space, which results in a variation in the threshold values of the exact decision statistic when the Neyman–Pearson criterion is used. The characteristics of the exact decision statistic and various approximate decision statistics are compared in detail. For the antenna arrays with a large number of elements, the influence of the used decision statistic on the target-missing probability is shown to become rather significant. A new combined decision statistic with the characteristics that are close to those of the exact decision statistic is introduced for a wide signal-to-noise ratio range.
8 citations
TL;DR: In this article, the integral parameters of resonant interaction of relativistic electrons in the Earth's radiation belts with electromagnetic ion-cyclotron waves were analyzed based on numerical simulations.
Abstract: We analyze the integral parameters of resonant interaction of relativistic electrons in the Earth’s radiation belts with electromagnetic ion–cyclotron waves. The analysis is based on numerical simulations. Wave packets of finite length with varying frequency and various amplitude profiles propagating from the equator are considered. The roles of three nonlinear interaction regimes, analyzed in the first part of our paper [1] for single particle trajectories, are compared. It is shown that interaction characteristics depend stronger on the electron energy and wave packet position for the wave packet with Gaussian amplitude profile than for the wave packet with constant amplitude. For the wave packet with Gaussian amplitude profile, the directed and diffusive transfer of particles in the phase space are comparable, while for the wave packet with constant amplitude the mean change in the equatorial pitch angle can be considerably (a factor of 3 to 5) greater than the standard deviation. The most significant decrease in the equatorial pitch angle and the largest fraction of the corresponding particles are obtained for particles with energies of about 1 MeV for the wave packet close to the equator. The fraction of particles which can be scattered into the loss cone after a single pass through the wave packet is 1.0–1.7%.
8 citations
TL;DR: In this paper, a singular integral equation with the Cauchy singularity is derived for the electric field of a microstrip antenna on a substrate made of a chiral metamaterial.
Abstract: We present a method for electrodynamic analysis of a microstrip antenna on a substrate made of a chiral metamaterial. Singular integral representations of the components of the electric field radiated by such an antenna are presented. A singular integral equation with the Cauchy singularity is obtained, which allows determining the function of the current-density distribution over the antenna surface. The dependences of the magnitude and phase of the electric-field components on the coordinates and the radiation patterns of the antenna are calculated. It is shown that the electromagnetic waves radiated by such an antenna have the elliptical polarization.
7 citations
TL;DR: In this paper, the effect of the ionospheric day-night non-uniformity on the electromagnetic field amplitude at the Schumann-resonance and higher frequencies was investigated.
Abstract: The real structure of the lower ionosphere should be taken into account when propagation of extremely low frequency (ELF) radio waves is modeled and the global electromagnetic (Schumann) resonance in the Earth–ionosphere cavity is studied. In the present work, we use a 2D telegraph equation (2DTE) to estimate the effect of the ionospheric day–night non-uniformity on the electromagnetic field amplitude at the Schumann-resonance and higher frequencies. The properties of the cavity are accounted for by using the full wave solution technique through conductivity profiles in the daytime and night-time conditions. Electromagnetic fields in the non-uniform cavity are found by using a 2DTE. Both the sharp terminator model and the model of a smooth day–night transition were considered. The main attention was focused on effects arising on 5000-km paths that are perpendicular or parallel to the solar terminator line. The data were computed for a series of frequencies. A comparison of the calculated data with observation results is also performed and an interpretation of the observed effects is given.
TL;DR: In this paper, the authors present the results of the theoretical and experimental studies aimed at developing pulsed gyrotrons with relativistic electron beams operating in the millimeter-wavelength range and retaining the multimegawatt power level.
Abstract: We present the results of the theoretical and experimental studies, which are aimed at developing pulsed gyrotrons with relativistic electron beams operating in the millimeter-wavelength range and retaining the multimegawatt power level. The use of the interaction at the second gyrofrequency harmonic, which is characterized by a sufficiently high efficiency and availability of the solution for the mode selection problem, allows one to double the generation frequency without increasing the magnetic field. In the corresponding experiment, the output radiation power exceeded 2 MW, and the efficiency was about 30% at a wavelength of 5.5 mm.
TL;DR: In this article, the authors presented a theoretical study and a computer simulation of the undulator radiation in single-pass free-electron lasers (FELs) with a two-frequency undulator and showed the possibility to achieve a hundredfold increase in the radiation intensity of the nth harmonic in a FEL, in which the electron-phase shift by kπ/n with respect to photons occurs between undulator sections.
Abstract: We present a theoretical study and a computer simulation of characteristics of the undulator radiation in single-pass free-electron lasers (FELs). Using a phenomenological model describing the dynamics of the radiated power in FELs with allowance for the basic loss, we study generation of harmonics in the X-ray range in a FEL with a two-frequency undulator. We study the possibility to achieve a hundredfold increase in the radiation intensity of the nth harmonic in a FEL, in which the electron-phase shift by kπ/n with respect to photons occurs between undulator sections, where k = 2, 4, . . . . The advantages of using a two-frequency undulator in a single-pass FEL and the possibility of generating the high-power X-ray radiation by the FEL at the harmonic wavelengths 2.3–3.3 nm in the linear regime are demonstrated. The FEL is compared with the two-frequency undulator and the conventional plane undulator. Additionally, generation of radiation having a power of tens of megawatts is studied at the wavelength λ ≈ 3.27 nm in a multistage FEL with a length of 40 m, an off-the-shelf excimer ultraviolet seed laser, which operates at a wavelength of 157 nm, and an electron beam having an energy of about 0.6 GeV.
TL;DR: In this article, the results of simultaneous measurements of the brightness temperature and the detonation front motion in a trinitrotoluene sample were performed using the EHF radiointerferometer radiometer developed at Yu. E. Sedakov Research Institute of Measurement Systems.
Abstract: We show the results of simultaneous measurements of the brightness temperature and the detonation-front motion in a trinitrotoluene sample. The measurements were performed using the EHF radiointerferometer radiometer developed at Yu. E. Sedakov Research Institute of Measurement Systems. The algorithms and the methods for the recorded-signal processing are described.
TL;DR: In this paper, the authors discuss the results of measuring characteristics of the artificial plasma disturbances excited at altitudes of 450-500 km with the ionospheric F2 layer modified by high-power HF radio waves from the Sura facility.
Abstract: We discuss the results of measuring characteristics of the artificial plasma disturbances excited at altitudes of 450–500 km with the ionospheric F2 layer modified by high-power HF radio waves from the Sura facility. It is found that at these altitudes there are plasma temperature and density variations in the HF-perturbed magnetic flux tube. No ducts with increased plasma density that were previously observed at altitudes of about 660 km were detected. The results of the studies are compared with the data from the DEMETER satellite and the results of radiotomographic measurements. It is noted that the field-aligned currents induced in a perturbed ionosphere during the Sura operation were detected for the first time using SWARM satellites.
TL;DR: A new variant of the superresolution method of minimum polynomial of the correlation matrix for estimating the number and angular coordinates of the closely located sources of the signals recorded by the antenna array is proposed.
Abstract: We propose a new variant of the superresolution method of minimum polynomial of the correlation matrix for estimating the number and angular coordinates of the closely located sources of the signals recorded by the antenna array. The method ensures the direction finding of the sources by determining roots of the denominator of the pseudospectral function (the root method). Special attention is paid to the cases of strongly correlated signal sources and a short sample of the input process when the number of samples is smaller than that of array elements. The efficiencies of the angular superresolution for the root and spectral variants of the method of minimum polynomial, as well as the root MUSIC (MUltiple SIgnal Classification) method are compared.
TL;DR: In this paper, the authors studied the possibilities of integral representation for the two-frequency mutual coherence function of the wave field in a randomly inhomogeneous ionosphere and obtained the integral representation using the Double Weighted Fourier Transform (DWFT) method.
Abstract: We study the possibilities of integral representation for the two-frequency mutual coherence function of the wave field in a randomly inhomogeneous ionosphere. The integral representation was obtained using the Double Weighted Fourier Transform (DWFT) method. We point out that the conditions of validity of the geometrical-optics approximation for frequency coherence are weaker than the same condition for individual samples. Examples of calculation of the frequency coherence functions for waves in the ionospheric plasma with the irregularities described by the Gaussian spectrum and Shkarofsky’s model are given. Simulation results show that diffraction effects reduce the width of the frequency coherence function. The capabilities of the methods for spatial processing of the wave field and its two-frequency mutual coherence function, which eliminate these effects through the Fresnel and DWFT inversions, are examined.
TL;DR: In this article, the authors considered a network of Kuramoto phase oscillators with randomly blinking couplings and analytically estimated the threshold coupling force for synchronizing the ensemble oscillators.
Abstract: We consider a network of Kuramoto phase oscillators with randomly blinking couplings. Applicability of the averaging method for small switching intervals is rigorously substantiated. Using this method, we analytically estimate the threshold coupling force for synchronizing the ensemble oscillators. The threshold synchronization is studied as a function of the switching interval for various network sizes. The effect of preserving synchronization for a significant increase in the switching interval is found, which is the key feature of the system since a slight increase in this interval usually leads to the synchronization failure. The intermittent-synchronization possibility for small network sizes and large switching intervals is shown. An increase in the network size is shown to result in a stability increase due to the decreasing probability of appearance of uncoupled configurations. The regions corresponding to the global synchronization of oscillators are singled out in the system-parameter space.
TL;DR: In this paper, a universal method of compensating for the arbitrary dispersion in the spectral and time domain optical coherence tomography systems is described, which allows one to obtain the spectrally determined resolution if the instrument function is close to the Gaussian one.
Abstract: We describe a universal method of compensating for the arbitrary dispersion in the spectral and time domain optical coherence tomography systems. In combination with the amplitude method of correcting the optical-spectrum irregularities, this approach allows one to obtain the spectrally determined resolution if the instrument function is close to the Gaussian one. The efficiency of the method is demonstrated in the time and spectral domain optical coherence tomographies with the fully fiber-type optical systems for the relative optical-spectrum width exceeding 10%.
TL;DR: In this article, the authors present the results of simultaneous measurements of the total electron content (TEC) of the ionosphere on the GPS signal path and the ionospheric artificial airglow in the atomic oxygen red line (λ = 630 nm) during HF pumping of ionosphere by the Sura facility radiation.
Abstract: We present the results of simultaneous measurements of the total electron content (TEC) of the ionosphere on the GPS signal path and the ionospheric artificial airglow in the atomic oxygen red line (λ = 630 nm) during HF pumping of the ionosphere by the Sura facility radiation. It is very likely that when the “navigation satellite—GPS receiver” path of a signal crosses the artificial airglow spot, the maximum brightness of the latter on the line of sight of the optical device at the navigation satellite was observed in the region of the TEC minimum.
TL;DR: In this article, the authors solved the problem of electrodynamic analysis of the mode composition of radiation in a circular waveguide with thin radial metal ribs and developed algorithms for calculation of cutoff wave numbers and components of the electromagnetic fields of the H and E modes.
Abstract: We solve the problem of electrodynamic analysis of the mode composition of radiation in a circular waveguide with thin radial metal ribs. Algorithms for calculation of cutoff wave numbers and components of the electromagnetic fields of the H and E modes have been developed with allowance for the singularity of the field behavior near a thin metal rib. Spectral characteristics of the waveguide are studied. Structures of the electromagnetic fields of the fundamental mode and the higher modes are determined.
TL;DR: In this article, the authors proposed a model for determination of the effective complex permeability of compacted metal-powder media based on the equality of the magnetic moment in a given volume of the media with the desired effective permeability to the total magnetic moment of metal particles in the external high-frequency magnetic field, which arises due to excitation of electric eddy currents in the particles.
Abstract: We propose a model for determination of the effective complex permeability of compacted metal-powder media. It is based on the equality of the magnetic moment in a given volume of the media with the desired effective permeability to the total magnetic moment of metal particles in the external high-frequency magnetic field, which arises due to excitation of electric eddy currents in the particles. Calculations within the framework of the proposed model allow us to refine the values of the real and imaginary components of the permeability of metal powder compacts in the microwave band. The conditions of applicability of the proposed model are formulated, and their fulfillment is verified for metal powder compacts in the microwave and millimeter wavelength bands.
TL;DR: In this article, the results of numerical modeling of decameter radio-wave propagation on a weakly oblique Vasilsk-Nizhny Novgorod path under conditions of traveling ionospheric disturbances are presented.
Abstract: We present the results of numerical modeling of decameter radio-wave propagation on a weakly oblique Vasilsursk—Nizhny Novgorod path under conditions of traveling ionospheric disturbances. A comparison is made with the chirp sounding data obtained in winter with an average solar activity. The direction–velocity characteristics of the wave-like disturbances are determined. It is shown that in the daytime, in a quiet magnetic environment, medium-scale wave-like disturbances of the electron density with sizes about 100 km, a period of 15 min, and relative amplitude δ ≈ 0.1 can be responsible for the crescent traces on the ionograms. The wave-like disturbances propagate at a velocity of 110 m/s at the angle β ≈ −45° to the horizon with the wave vector oriented predominantly in the east–west direction.
TL;DR: In this paper, a numerical simulation of the evolution of wind waves is performed based on solving the Euler equations for a two-dimensional potential flow and allows for the nonlinear effects.
Abstract: We perform a numerical simulation of evolution of the wind waves, which is based on solving the Euler equations for a two-dimensional potential flow and, therefore, allows for the nonlinear effects. Analysis of the obtained realizations of the surface profiles shows that the proposed direct numerical simulation allows one to reproduce the features of modulation of short surface waves. The model dependence, which describes the characteristic deviation of the spectral density from the dispersion curve on the frequency–wave number plane, is obtained. Comparison with the wave spectra measured under natural conditions is indicative of a qualitative agreement between the calculated and experimental results.
TL;DR: In this article, the authors considered the possibility of generating the second and fourth optical harmonics of laser pulses having a central wavelength of 1030 nm with retaining the three-dimensional quasi-ellipsoidal intensity distribution.
Abstract: We consider the possibility of generating the second and fourth optical harmonics of laser pulses having a central wavelength of 1030 nm with retaining the three-dimensional quasi-ellipsoidal intensity distribution. The presented results of numerical simulation confirm that angular chirping allows one to retain the three-dimensional structure of the intensity distribution and enhance energy conversion. The proposed approach was tested experimentally using non-profiled laser beams. Energy conversion efficiency of 53% and 21% was achieved in the generation of the second and fourth harmonics, respectively.
TL;DR: In this article, the authors considered a low-power frequency-tunable gyrotron with an oversized cavity, which is designed for the purposes of nuclear magnetic resonance spectroscopy and other applications and operates in the 0.20-0.27 frequency range.
Abstract: We consider the main features of a low-power frequency-tunable gyrotron with an oversized cavity, which is designed for the purposes of nuclear magnetic resonance spectroscopy and other applications and operates in the 0.20–0.27 frequency range producing an output power of 200 W. We study the possibilities of wideband output frequency tuning by exciting a sequence of modes with similar caustics using magnetic-field variations and smooth tuning due to the excitation of modes with a great number of longitudinal variations. Aiming at widening the frequency tuning range, we also analyzed the possibility of smooth frequency tuning determined by controlled variations of the cavity temperature. Specific features of the electron-optical system of such a gyrotron is discussed, along with the possibility of increasing its efficiency by means of single-stage recovery of the residual energy of the electron beam.
TL;DR: In this paper, it was shown that the backward obliquesounding signals recorded on the Cyprus-Rostov-on-Don path are caused by the sideband scattering of radio waves from the Caucasus mountain ranges, the Iranian highlands, and the Balkan mountains.
Abstract: We realize the possibilities for positioning of ionospheric irregularities and the Earth’s surface roughness with the chirp-signal ionosonde–radio direction finder used as an over-the-horizon HF radar of bistatic configuration on the Cyprus — Rostov-on-Don and Australia — Rostov-on-Don paths. It is established that the small-amplitude diffuse signals coming from azimuths of 310°–50° on the Cyprus — Rostov-on-Don path in the evening and at night at frequencies above the maximum observable frequency (MOF) of the forward signal are due to backscattering by small-scale irregularities of the mid-latitude ionospheric F Layer. It is shown that the backward obliquesounding signals recorded on the Cyprus — Rostov-on-Don path are caused by the sideband scattering of radio waves from the Caucasus mountain ranges, the Iranian highlands, and the Balkan mountains. It is found that the anomalous signals observed on the Alice Springs (Australia) — Rostov-on-Don path, which come from azimuths of 10°–25° with delays by 10–16 ms exceeding the delay of the forward signal are due to scattering of radio waves by the high-latitude ionospheric F-layer irregularities localized in the evening sector of the auroral oval at latitudes of 70°–80° N.
TL;DR: In this article, the authors estimate thermal aberrations in Cr:CdSe and Cr:ZnSe chalcogenide crystals exposed to continuous-wave electromagnetic radiation at a wavelength of 1907 nm.
Abstract: We estimate thermal aberrations in Cr:CdSe and Cr:ZnSe chalcogenide crystals exposed to continuous-wave electromagnetic radiation at a wavelength of 1907 nm. Using the SIMULIA Abaqus software suite, deformation of such materials during their heating due to absorption of part of the radiation is simulated numerically. On the basis of the obtained results, the focal distances of the lenses induced in crystalline media are calculated by the matrix optics method.
TL;DR: In this paper, the power-law index at room temperature for the absorption coefficient of some amorphous polymers was determined on the basis of the dynamics of transmission of a broadband picosecond terahertz pulse through the polymer sample.
Abstract: The power dependence α(ν) ∝ νμ, where μ > 0 is the power exponent which is noninteger in the general case, is observed for amorphous polymers with a small absorption coefficient α in the low-frequency part of the terahertz range, which approximately corresponds to the frequencies ν from 0.1 to 2–3 THz. This dependence is fractal, which is due to the fractal structure of the polymer macromolecules. In this work, we find the power-law index at room temperature for the absorption coefficient of some amorphous polymers. This index is determined on the basis of the dynamics of transmission of a broadband picosecond terahertz pulse through the polymer sample, i.e., using the method of the pulse terahertz spectroscopy in the time-domain representation.
TL;DR: In this article, the authors considered the possibility of creating a compact high-power neutron generator with a small emitting area (of the order of 100 μm) and a neutron yield of 1010s−1 on the basis of a deuterium-deuterium fusion reaction.
Abstract: We consider the possibility of creating a compact high-power neutron generator with a small emitting area (of the order of 100 μm) and a neutron yield of 1010s−1 on the basis of a deuterium–deuterium fusion reaction (or 1012 s−1 on the basis of a deuterium–tritium fusion reaction). The fusion takes place under bombardment of a deuterium- (or tritium-) saturated target by a high-current (about 100 mA) focused deuterium ion beam with an energy of ~ 100 keV. The ion beam with total current at a level of hundreds of milliamperes and small emittance (less than 0.1 π·mm·mrad), which is crucial for sharp focusing, can be generated by a quasi-gas-dynamic ion source of a new generation created on the basis of a discharge in an open magnetic trap sustained by high-power electromagnetic radiation of the millimeter wavelength range under electron cyclotron resonance conditions. Simulations of the focusing system for the experimentally obtained ion beam show the possibility to create a deuterium ion beam with a transverse size of 200 μm on the neutron-forming target. Prospects for using such a neutron source for neutron tomography are discussed.