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It is proposed to use the tomographic approach to the problem of detecting and imaging concealed utility networks. This approach is based on generating the three-dimensional radio images of the space being explored from the results of measuring its location wave projections in a dual-polarization measurement mode. The problem is solved by focusing radiation first on the “air–dielectric” interface and then inside the dielectric. Experimental data processing results and reconstructed threedimensional radio tomograms are provided for a “twisted pair” cable and a fiber-optic cable with no metallic inclusions. The results confirm the operability of the approach.

The heat transfer processes associated with the heating of the operating liquid and the calibration of the liquid calorimeters for measuring the energy of high-power microwave pulses are studied analytically and by numerical simulation. It is shown that convection significantly enhances heat transfer between the calibration and thermostabilization heaters and the operating liquid, hence, it helps to reduce the formation of bubbles in the volume of the operating liquid when controlling and calibrating the calorimeter. Heat transfer from tape heaters is noticeably more efficient than that from single wire ones. The results obtained are essential for the development of liquid calorimeters and the adjustment of their operating modes.

The paper describes a study of a new relativistic microwave Cherenkov generator of millimeter wavelength range with the transverse dimension of the electrodynamic system D>2.5λ, where D is the average diameter of the slow wave structure, and λ is the radiation wavelength. The investigations were carried out with a high-current SINUS-200 electron accelerator at a voltage of 473 kV and an electron beam current of 3.8 kA. The use of several, complementing each other, mechanisms of suppression of parasitic waves provides stable microwave generation at a specified frequency of 36.4 GHz. The microwave power in the experiment 804 MW with 45% beam-to microwave power conversion.

The dynamics of breakup of the compressed state of an electron beam with a virtual cathode (VC) transported in a two-section drift tube of a high-current electron accelerator has been studied. Based on the results of numerical simulations, the method of partial capture of the injected beam current during the applied voltage pulse is proposed and implemented, which can ensure the conditions necessary for the breakup of the electron beam compressed state. The VC velocity during the breakup of the electron beam compressed state amounts to 6–8% of the velocity of light in vacuum. The experimental data qualitatively agree with the results of analytical estimations and numerical simulations.

The mode convertor design of fundamental coaxial TEM to the lowest asymmetric TE11-mode of a circular waveguide was proposed and optimized with ANSYS HFSS software. It includes axially aligned parts: the input coaxial line with the high voltage insulator, conical coaxial matching line, wave-coax transition section and output circular waveguide. The most losses in this type of convertor caused by the wave of coaxial TE11-mode running back to the microwave source. To minimize these losses, there is the matching conical coaxial line with the cut-off insertion for coaxial TE11-mode. Characteristics of the convertor are as follows: the maximum input peak power – 3GW, the input impedance – 28Ohm, the central operating frequency – 1.14GHz. The power conversion efficiency to the output mode is from 90% upto 100% in the frequency band of 20%.

An electron beam with a virtual cathode (VC) transported in a two-section drift tube of a SINUS-7 high-current electron accelerator has been studied. The dependence of the VC velocity on the injected current has been experimentally determined for the first time. It is established that the VC motion in the drift tube is accompanied by microwave oscillations, which are caused by transient processes involved in the formation of a compressed electron beam.

On of the possible methods of obtaining monochrome X-ray radiation short “flashes” is parametric X-ray radiation (PXR) generated by the nanosecond duration electron beam. For this purpose the powerful electron beam effect on the tungsten crystalline target has been investigated experimentally. The accelerator of the direct effect “Sinus-7” has been used as an electron source, where the electron beam is formed in the flat vacuum diode in the magnetic field. The accelerating pulse duration is 50 ns, the electron energy is 1.1 MeV, the current density on the target surface is ~ 250 A/cm

In recent years, oil and gas exploration are increasingly turning to direct methods to identify accumulations of hydrocarbons (magnetometry, radiometry, geochemical methods, etc.). Similar works are tested high in the Tomsk region, near the Ob basin. In this paper we present some results of testing of geological and genetic models and radiogeochemical occurrence of hydrocarbons in relation to various oil and gas complexes, with the development of neural network methods of analysis and forecasting, formulated proposals for their integrated use.

The paper deals with the application features of capacitive probes for subnanosecond voltage pulse measurements. The relation for the amplitude of distortions determined by the finite electrical length of a capacitive divider was obtained. This relation could serve for quantitative estimation of capacitive divider suitability. Probes of various designs were used for recording the high voltage pulses with subnanosecond voltage changes. The pulse shapes with voltage change durations of 0.2 - 20 ns from different voltage probes were compared. It was shown that the use of capacitive divider with high- and low-voltage arms filled with the same material is more appropriate. This divider provides the same voltage ratio for voltage changes of durations from tens to fractions of nanoseconds.

Accumulation of electrons in course of transportation of tubular high-current electron beam in a coaxial diode with magnetic insulation was studied in the situation of counterstream electron motion occurring due to the formation of a virtual cathode. Accumulation of electrons in these flows is accompanied by gradual increase in their relative energy spread and simultaneous decrease in the maximum kinetic energy. The process is described analytically and confirmed in numerical modeling. The theory is an extension of the known theory of coaxial magnetically insulated diode (based on the conservation of axial component of the generalized momentum) taking into account the spread of electron energies. The numerical modeling employed the KARAT electromagnetic PiC-code. Experiments were performed using high-current electron accelerator SINUS-7 (pulsewidth 50 ns) in the range of diode voltages 350—800 kV, magnetic fields 8—24 kOe, electron beam currents 2—12 kA. A gradual increase of potential of the electron beam between the explosive-emission cathode and the virtual cathode was observed, which accompanies accumulation of circulating electrons as predicted in theory.

This paper studies the motion of a virtual cathode in a two-section drift tube with the formation and breakup of the “compressed” state of an electron beam. Experimental arrangements to intercept part of the injected current during the voltage pulse and to provide virtual cathode motion toward the collector are proposed. The arrangements were implemented on the SINUS-7 high-current electron accelerator. Theoretical and experimental dependences of the virtual cathode velocity on the injected current and cathode voltage are presented. The experimental data on virtual cathode motion agree with its theoretical model based on analytical solutions of equations assisted by computer simulation with the PIC code KARAT. The results of the work demonstrate the feasibility of controlling the virtual cathode motion which can be used in collective ion acceleration and microwave generation.