Problem of immunity of the electronic devices under powerful electromagnetic emission as well as mechanism of device response at out-of-band emission influence are discussed. Parameters which characterize level of emission influence on device are indicated. The method of the empirical estimation of threshold level of these parameters, which characterize immunity of device under the influence of ultra-wideband (UWB) emission is proposed.

A method of empirical evaluation of the transient response of an aperture-type antenna when it is excited by a video pulse has been proposed. The evaluation was carried out on the basis of comparing the excitation voltage of the antenna and the excitation voltage of the radiating aperture, which is calculated using the parameters of the emitted pulse. An evaluation of the energy efficiency of a given antenna as a converter of electrical energy into radiation energy has been given through variations in the antenna length and duration and shape of its excitation pulse.

Active synchronized antenna arrays generating ultra-wideband radiation with an electric field strength of about 1 V/m at a distance of several hundred kilometers have been studied. They are designed to study the passage of ultra-wideband signals in the surface layer of the atmosphere and through the ionosphere. Synchronous antenna arrays with four and nine radiating modules have been created. Their radiation has a symmetrical radiation pattern along the x and y axes with a pulse duration at half-height of about 100 ps. They have a pulse energy potential (E × R) of about 60 and 150 kV, with a gross weight of 50 and 100 kg, respectively. Such characteristics allow these arrays to be placed on air carriers. The option of using air balloons under irradiation in the surface layer of the atmosphere and the option of placing meteorological rockets under irradiation from a height of 300 km to the Earth’s surface is considered.

Field experiments were carried out to measure ultrawideband subnanosecond radiation pulses in the time domain, taking into account the influence of reflection from the Earth’s surface. The results of these experiments make it possible to prepare experiments in the free atmosphere on real paths of 10 km or more in length. A technical solution for the use of a single-channel ultrawideband emitter with a pulse duration of about 50 ps, which is optimal in terms of weight and size characteristics and lifting to heights of up to 1000 m, is substantiated. A specially designed measuring antenna in the form of a passive antenna array with high sensitivity is used as a receiving measuring channel.

The results of the first direct experiments on the passage of pulses of ultra-wideband radiation of subnanosecond duration in the Earth’s atmosphere at a distance of more than 10 km are presented. In contrast to the work calculated, the preservation of the amplitude–time shape of the pulses in the process of increasing the distance is shown. The establishment of this fact is of decisive importance in the practical application of ultra-wideband pulses in new technological developments.

Предложена методика эмпирической оценки переходной характеристики антенны апертурного типа при ее возбуждении видеоимпульсом. Оценка проведена на основе сравнения напряжения возбуждения антенны и напряжения возбуждения излучающего раскрыва, которое вычислено по параметрам излученного импульса. Дана оценка энергетической эффективности заданной антенны как преобразователя электрической энергии в энергию излучения при вариации длины антенны, длительности и формы импульса ее возбуждения.

Field experiments have been carried out to measure ultra-wide-band subnanosecond radiation pulses in the time domain, taking into account the influence of reflection from the Earth's surface. Received results allow us to prepare experiments in a free atmosphere on real ranges of 10 kilometers or more in length. The optimal technical solution in terms of weight and size characteristics and elevation to heights up to 1000 meters is the using a single-channel ultra-wideband radiator with a pulse duration of about 50 ps and a specially designed measuring antenna in the form of a passive antenna array with high sensitivity.

Several problems of the analysis of parameters characterizing directional character of the aperture radiation under excitation by an ultrawideband signal are considered. Efficient concentration of the radiation energy in a narrow beam and the energy efficiency of the conversion of electric energy into the energy of directed ultrawideband radiation are estimated. The problem is solved with the aid of analytical estimates and numerical calculations using an idealized model of a plane aperture under synchronous and equal-amplitude excitation.

A calculation model of a plane aperture with nonuniform asynchronous excitation is constructed. The calculated results are in good agreement with the experimental data for a prototype of an ultrawideband emitter. Energy conversion efficiency in the emitter path from the power supply source of the antenna-feeder system to the radiation energy in the main lobe of the radiation pattern is estimated. Limiting values of such an efficiency and specific weight parameters of the emitter are also determined.

Tatarskii, a prominent physicist and a correspondingmember of the Russian Academy of Sciences. V I Tatarskii is world renowned and acknowledged for his fundamental contributions on the theory of wave propagation in randomly inhomogeneous media. The results of these studies have been applied to of fundamental problems of turbulence and organized structures in the lower, middle, and upper atmosphere. The asymptotic formulations obtained by V I Tatarskii are widely used to solve applied problems of long-range radio communication and radio navigation, to estimate the influence of atmospheric turbulence on laser radiation propagation and on the image of astronomical objects in telescopes, to develop methods and systems of adaptive optics, scintillometry, and acoustic and radioacoustic ground-based sensing of the atmospheric boundary layer and satellite radio occultation of Earth's and other planets' atmospheres. Valerian Il'ich Tatarskii was born in Kharkov. His father was an engineer and in the 1920s±1930s took part in building many large industrial enterprises in the USSR. For this reason, the Tatarskiis often moved from one place to another (his mother was a homemaker). Valerian went to school in Kharkiv and finished with a gold medal in Krasnoyarsk, where his family was evacuated from Kharkiv at the beginning of the war, together with the plant at which his father worked. Immediately after school, Valerian entered the Physical Faculty of Moscow State University (MSU). While studying at the Physical Faculty of MSU (1947± 1952), V I Tatarskii already became interested in the influence of turbulent inhomogeneities on sound propagation. This problem underlaid his diploma work, which he did under the guidance of Professor V A Krasil'nikov. On graduating from MSU, he went to work at the Geophysical Institute of the USSRAcademy of Sciences at the Laboratory for Turbulence Research, where he continued working in this field under the guidance of A M Obukhov. V I Tatarskii significantly developed theories of sound scattering and propagation of acoustic and electromagnetic waves in random media, which were originally proposed by A M Obukhov in the 1940s± 1950s, and covered a wider range of topics. To solve these problems, V I Tatarskii modified and put to wide use the method of smooth perturbations proposed earlier by SM Rytov to solve the problem of light diffraction by ultrasound and then used by A M Obukhov to allow for diffraction in the propagation of acoustic and light waves in a turbulent medium. These results lay the basis for his candidate thesis and his monograph, ``The theory of fluctuation phenomena upon wave propagation in a turbulent atmosphere,'' published in 1959 and then abroad in English in 1961 (Tatarskii V I Wave Propagation in a Turbulent Medium (New York: McGrawHill, 1961)). Continuing his work at the Institute of Atmospheric Physics, which split in 1956 from the Geophysical Institute, V I Tatarskii went on developing his approaches in the theoretical description of wave scattering and propagation in randomly inhomogeneous media using increasingly powerful mathematical methods. These approaches were reflected in his doctoral thesis (1964) and in the monograph, ``Wave propagation in a turbulent atmosphere,'' whose issue in English in 1971 (Tatarskii V I The Effects of the Turbulent Atmosphere on Wave Propagation (Springfield: National Technical Information Office, 1971)) became very popular among foreign specialists. V I Tatarskii did not confine himself to purely theoretical studies, working fruitfully with his colleagues and experimentalists, in particular with A S Gurvich. He participated Uspekhi Fizicheskikh Nauk 189 (10) 1125 ± 1126 (2019) DOI: https://doi.org/10.3367/UFNr.2019.08.038659 Translated by M V Tsaplina PERSONALIA PACS number: 01.60.+q

The paper considers the perspective of using powerful semiconductor subnanosecond electrical pulse generators as radiation modulators. We give the data on determining the amplitude-time and spectral radiation parameters of a synchronous active antenna array, the angular divergence of the array radiation. We also estimate the efficiency of converting the electric excitation energy of the antennas into the energy of the directed ultra-wideband radiation in the main directional lobe. Findings of the research show that the effective peak radiation power of the terawatt level is reached at the excitation power of the gigawatt level, and the effective average radiation power of tens of megawatts is achieved with the primary power consumption of modulators of tens of kilowatts.

Results of creation, operation, and diagnostics of the high power radiators for ultra-short length electromagnetic pulses (USEMPs) with a quasi-unipolar profile, which have been developed in our laboratory, are presented. The radiating module contains: the ultra-wideband (UWB) antenna array, the exciting high voltage pulse semiconductor generator (a pulser), the power source and the control unit. The principles of antenna array with a high efficiency aperture about 0.9 were developed using joint four TEM-horns with shielding electrodes in every TEM-horn. Sizes of the antenna apertures were (16-60) cm. The pulsers produced by "FID Technology" company had the following parameters: 50 Ohm connector impedance, unipolar pulses voltages (10-100) kV, the rise-time (0.04-0.15) ns, and the width (0.2-1) ns. The modules radiate the USEMPs of (0.1-10) GHz spectrum, their repetition rate is (1-100) kHz, and the effective potential is E*R = (20-400) kV, producing the peak E-field into the far-zone of R -distance. Parameters of the USEMP waves were measured by a calibrated sensor with the following characteristics: the sensitivity 0.32V/(kV/m), the rise-time 0.03 ns, the duration up to 7 ns. The measurements were in agreement with the simulation results, which were obtained using the 3-D code "KARAT". The USEMP waves with amplitudes (1-10) kV/m and the pulse repetition rate (0.5-100) kHz were successfully used to examine various electronic devices for an electromagnetic immunity.

Processes of nuclear burning of various elements in the scheme of a compact inertial electrostatic confinement implemented on the basis of a nanosecond vacuum discharge (NVD) with low-energy hollow cathode were investigated experimentally earlier. This paper presents the results of a recent series of DD fusion experiments on the newly created experimental set-up NVD-2 combined with x-ray and neutron yield diagnostics. The voltage-current (VA) characteristics of the discharge, and the regimes of generation of x-ray and DD neutrons realized experimentally are presented and discussed. The experimental results are compared with the results of particle-in-cell simulation of the nuclear DD fusion processes in NVD using electrodynamic code KARAT. Recent series of DD fusion experiments have reproducing in TOF scheme some basic features of DD neutrons yield observed earlier. Meanwhile, the analysis of V-A characteristics and anode erosion shows that efficiency of energy deposition at initial stage of discharge is still insufficient, and the ways to optimize the electrophysical processes at NVD-2 are clarified.

In this paper, we continue the discussion of the experimental results on the yield of DD neutrons and hard x-rays in the nanosecond vacuum discharge (NVD) with a virtual cathode, which was started in the previous article of this issue, and previously (Kurilenkov Y K et al 2006 J. Phys. A: Math. Gen. 39 4375). We have considered here the regimes of very dense interelectrode aerosol ensembles, in which diffusion of even hard x-rays is found. The yield of DD neutrons in these regimes is conditioned not only by the head-on deuteron-deuteron collisions in the potential well of virtual cathode, but also by the channel of "deuteron-deuterium cluster" reaction, which exceeds overall yield of neutrons per a shot by more than an order of magnitude, bringing it up to ∼ 107/(4π). Very bright bursts of hard x-rays are also represented and discussed here. Presumably, their nature may be associated with the appearance in the NVD of some properties of random laser in the x-ray spectrum. Good preceding agreeing of the experiment on the DD fusion in the NVD with its particle-in-cell (PIC) simulations provides a basis to begin consideration of nuclear burning "proton-boron" in the NVD, which will be accompanied by the release of alpha particles only. With this objective in view, there has been started the PIC-simulation of aneutronic burning of p-B11, and its preliminary results are presented.

The design and parameters of a compact radiator of high-power electromagnetic nanosecond pulses designed for simulation of ultra-wideband exposures in electromagnetic compatibility problems are described. It is shown that the effective pulse power of the radiator is 3 GW in the forward traveling wave and 15 GW in the wave reflected from the reflector. The effective density of the continuous energy spectrum is 17 mJ/MHz at 0.3 GHz.

Приведено описание конструкции и параметров компактного излучателя мощных электромагнитных импульсов наносекундной длительности, предназначенного для моделирования сверхширокополосных воздействий в задачах электромагнитной совместимости. Показано, что эффективная импульсная мощность излучателя составляет в прямой волне 3 ГВт, а в отраженной от рефлектора – 15 ГВт. На частоте 0.3 ГГц эффективная плотность сплошного энергетического спектра излучения равна 17 мДж/МГц.

The design and characteristics of powerful nanosecond UWB pulse source intended for study of particular electromagnetic compatibility problems are given. For excitation of UWB source we use high voltage drive-pulse generator based on resonance transformer. Power supply is a set of nickel metal hydride rechargeable batteries. Designed source of radiation is characterized by the following parameters: voltage output of the generator is approximately U-G approximate to 550 kV, field range product (FRP = E x R) equals to 300 kV (with reflector 670 kV approx.), effective radiated power (ERP) is approximately 3 GW (15 GW). Peak energy spectrum at the frequency of 0.3 GHz is 17 mJ/MHz. Pulse-repetition frequency is adjusted within 0 to 1 kHz range. Parabolic reflector is about 1.2 x 1.2 x 0.6 m overall. The source as a whole is combined into monoblock of 1 m high and 0.24 m in diameter. Total weight of the source is 65 kg approximately.