Powerful pulsed electrophysical transformers from the Institute of High-Current Electronics,Siberian Branch of the Russian Academy of Sciences

Problems in the creation and exploitation of powerful pulsed electrophysical transformers, developed at the Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences, are discussed. The power of the largest installations is 2.5·10¹² W (pulsed). The small size, the outside location of the main components requiring maintenance, and the absence of large volumes of transformer oil make the pulsed transformers competitive with pulsed voltage generators. Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 58–66, December, 1995.     

Resonance laser actions as an efficient method for control of the gas and plasma states

The results obtained by the authors in studies of the mechanical action of resonance laser light on gas and plasma are briefly reviewed. L. V. Kirenskii Institute of Physics of the Siberian Branch of the Russian Academy of Sciences; Institute of Computational Modeling of the Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 96–105, August, 1999.     

Features of evolution of the substructure in the creep of dispersion-hardened nickel

A study is made of the laws governing high-temperature creep and the evolution of the substructure in dispersion-hardened alloy Ni — 3 vol. % HfO₂ during its free annealing and creep. The polygonized substructure was formed in the alloy prior to annealing. An analysis is made of structural transformations at different structural levels and the mechanism of high-temperature creep in the alloy. Institute of the Physics of Strength and Materials Science, Siberian Branch of the Russian Academy of Sciences. All-Republic Engineering-Technical Center, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 83–89, March, 1998.     

Generation of hard breaking radiation on the MIG system with a plasma opening switch

This paper presents the results of experiments on the generation of pulsed γ radiation of average photon energy ∼1.2 MeV and duration ≤20 ns on the MIG system with a plasma opening switch. Operating modes with a maximum dose downstream of the anode of (1–2)·10¹³ and 10¹² R/s over an area of 2–3 and 100 cm² are obtained, respectively. Institute of High Current Electronics, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 26–30, December, 1999.     

Experiments on the GIT-4 with the load connected upstream of the plasma opening switch

Experiments have been performed on the GIT-4 generator with a plasma opening switch to study the operation of a circuit connecting the load and the switch through an untriggered spark gap depending for its operation on a discharge over the surface of a dielectric in vacuum. The current switching into inductive loads of different inductance was investigated. The dependence of the time the switch is open on load inductance has been found. It has been demonstrated that the surface-discharge spark gap can be used at current rise rates of up to ∼2·10¹³ A/s. Institute of High Current Electronics, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 31–35, December, 1999.     

Powerful pulsed source of seismic oscillations

A source of seismic oscillations for surface and borehole seismic prospecting is described. The source was developed at the Institute of High-Current Electronics Siberian Branch, Russian Academy of Sciences. The results of preliminary field tests are reported, and the prospects for further improvement are discussed. Deceased Institute of High-Current Electronics, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 100–104, December, 1997.     

Wide-aperture electric-discharge XeCl lasers

Experimental investigations have been performed for aXeCl laser with the active region aperture equal to 6.5×7 and 15×15 cm. To pump the laser, two types of generator were used: a generator connected in a double-loop circuit with a peaking capacitor and a multichannel spark gap switch and a magnetic thyratron generator. The working mixtureNe−Xe−HCl was preionized with soft x rays and a low-current electron beam, providing an initial electron density ranging from 10⁶ to 5·10¹³ cm⁻³. Conditions in which a homogeneous space discharge is initiated have been studied. It has been investigated how the degree of ionization of the gas and the aperture of the active region affect the discharge and lasing characteristics of the laser. The laser efficiency reaches 4% with an energy of ≈ 6 J extracted from one liter of the active region. Institute of High-Current Electronics, Siberian Division of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 54–59, April, 2000.     

Generation of droplets emitted by pool explosive-emission cathodes

The velocity spectrum of droplets emitted by a pool explosive-emission cathode was studied. Relation between sizes of droplets and its maximal velocities over the range of 10³−18×10⁴ cm/s have been found. The dependence obtained confirms the mechanism found earlier for the droplet emission under high pressures developed in explosive emission centers. Institute of High Current Electronics. Siberian Division of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 105–109, March, 1999.     

A study of possibilities of development of GaAs detectors for high-power nanosecond X-ray pulses

It is proposed to use chromium-compensated semi-insulating GaAs detectors for detecting high-power nanosecond X-ray pulses. An X-ray facility based on a small direct-acting electron accelerator “Sinus-150” developed at the Institute of High-Current Electronics of the Siberian Branch of the Russian Academy of Sciences, Tomsk was used as a source of pulsed X-ray radiation. The detectors are shown to detect 5 ns pulses under exposure to 30 mR radiation during one pulse without distortions. In so doing, one-ampere currents flow through the active detector area 0.2 cm². It is found that the physical processes limiting the working capacity of GaAs detectors are due to capture of nonequilibrium electrons and holes by deep centers. At the nonequilibrium charge-carrier concentrations higher than 5·10¹³ cm³, nonuniform distributions of the electric field are formed in the active region and these can result in distortion of the output detector signal shape. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 14–18, September, 2008.     

Uncontrollable multichannel commutator in the output cascade of the SNOP-3 generator

A multichannel uncontrollable submersible commutator is described. The commutator is tested in the output cascade of the SNOP-3 generator in the discharge of a signal-forming line with a wave resistance of 0.65 Ω to a transmission line with the same wave resistance and an inductive load of 30 nH. The inductance and ohmic resistance of the commutator are determined (15–20 nH and 0.2 Ω, respectively). With the inductive load of 30 nH, a rate of current increase of 3·10¹³ A/sec is obtained. A special commutator design with a screened grounded plane is tested; this design permits reduction in the prepulse voltage at the load to 0.25% of the voltage at the signal-forming line. Institute of High-Power Electronics, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 67–72, December, 1995.     

Broadband radiation from rare-gas plasmas excited by a modulated rf discharge

An investigation was made of plasma radiation spectra created by a modulated rf discharge having an anomalously low operating voltage, in krypton, xenon, argon, and neon. Broadband radiation was recorded in the ultraviolet and visible spectral regions.Institute of High-Current Electronics, Siberian Branch, Russian Academy of Sciences. Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 32–36, October, 1995.     

Molar coefficients of extinction for IR absorption bands of Ni(II) acetylacetonate, ketoiminate, and trifluoroacetylacetonate

We have studied IR absorption spectra (within the spectral range of 4000-200 cm⁻¹ of the intracomplex chelate compounds Ni(II) bis-acetylacetonate, Ni(II) bis-ketoiminate, and Ni(II) bis-trifluoroacetylacetonate and have given a full interpretation and comparison of the spectra of these compounds in dissolved and solid states. The reasons for the differences in the spectra are discussed. The molar coefficients of extinction for the absorption bands are calculated. Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Akad. Lavrent’ev Ave., Novosibirsk, 630090, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 775–780, September–October, 1998.     

Change in structure and properties of carbon steels bombarded by a 10−5 to 10−4 second high-energy electron beam

We consider the hardening characteristics and features of the structural and phase transformations in carbon steel (0.7% C) quenched from the melt using an electron beam with electron energy 130–180 keV, pulse duration 10–200 msec and power density 10⁶ to 10⁷ W/cm². We have observed that maximum hardening is achieved for pulse duration 40 msec. The nonmonotonic character of the dependence of the degree of hardening on the pulse duration is connected with the substantial effect of the beam parameters on the phase composition and morphology of the rapidly quenched structures.Institute of Power Electronics, Siberian Branch, Russian Academy of Sciences; Tomsk State Architectural Design Academy. Institute of the Physics of Strength and Materials Science, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, p. 42–50, October, 1995.     

Laser interferometry of acoustic fields generated by high-current electron beams in solids

We have developed a method for detecting acoustic fields in solids irradiated with dense electron beams. The method is based on laser Michelson interferometry. The electron source is a high-current DZhIN electron accelerator. The detection system features a short baseline Michelson interferometer located inside the experimental chamber with the sample, a stabilized initial beam pathlength difference within the interferometer, high temporal resolution, an analog-to-digital converter with output to a personal computer, and a program for reducing the interferometer data. We can measure both long pulses with minimum displacements of 10⁻¹⁰ m and durations of 10⁻⁸ sec, and flexure waves with large-amplitude displacements of 10⁻⁵ m and oscillation periods of 10⁻³ sec. We present results from studies of flexure waves in thin plates and rods of copper, silicon, alkali-halide crystals, quartz glasses, and D16T aluminum alloy irradiated by nanosecond high-density electron beams. Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 82–92, November, 1997.     

High-power Čerenkov microwave oscillators utilizing High-Current nanosecond Electron beams

A short review is given of results obtained at the Institute of High-Current Electronics of the Siberian Branch of the Russian Academy of Sciences on generating high-power microwave radiation. Most of the research was devoted to a study of stimulated Čerenkov radiation from relativistic electron beams. It is shown that the efficiency of a relativistic 3-cm backward wave tube with a nonuniform coupling resistance can reach 35%. High-frequency radiation was discovered in the emission spectrum of the Čerenkov oscillators and it was shown that the nature of the radiation was associated with the stimulated scattering of low-frequency radiation by the relativistic electrons. Radiation with a power of 500 MW was obtained in the 8-mm wavelength range using a two-beam Čerenkov oscillator. High-current pulse-periodic nanosecond accelerators with a charging device utilizing a Tesla transformer were used in the experiments. The possibility was demonstrated of generating high-power microwave radiation with a pulse-repetition frequency of up to 100 Hz. An average power of ∼500 W was achieved from the relativistic oscillators. A relativistic backward wave tube with a high-current electron beam was used to make a prototype nanosecond radar device. Some of the results presented were obtained jointly with the Russian Academy of Sciences Institute of Applied Physics. Questions concerning multiwave Čerenkov interaction are not considered in this paper. Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences, Tomsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 5–20, December, 1996.     

Extended representation of the lorentz transformations

An extended variant of the solution of the generalized Lorentz transformations (their particular solution is Einstein's special theory of relativity) is suggested in which the experimentally recorded physical quantity c⁻¹ (time) rather than the anisotropic velocity of light c is considered invariant for a quasi-closed light trajectory. The theory explains the Sagnac vortex effect and the negative result of experiments of the Michelson-Morley type. The theory can be tested experimentally against the transverse Doppler effect. Samara Branch of the P. N. Lebedev Physical Institute of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 8–14, July, 1999.     

High-power electron ring beams as x-ray sources for uniform irradiation of large-area objects

The paper substantiates the use of high-current megavolt diodes with a ring cathode and a high aspect ratio (R/d≫1) as radiation sources for irradiating objects with a large area (500–1000 cm²). The size of the irradiated area is shown to depend weakly on the nature of the angular dependence of the radiator for moderate energies (0.5–1.5 MeV) of accelerated electrons. Institute of Strong-Current Electronics, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 40–44, December, 1995.     

Influence of cosmic ray variations on cloudiness distribution over Northern Asia

Influence of cosmic ray (CR) flux variations on cloudiness over Northern Asia is investigated based on NOAA satellite images and data of neutron monitors of the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences (ITMIRWP RAS, Moscow) and Institute of Cosmophysical Research and Aeronomy of the Siberian Branch of the Russian Academy of Sciences (ICPRA SB RAS, Yakutsk). The influence of the Forbush decrease of the CR intensity on the latitudinal distribution of the cloud cover is demonstrated. A positive correlation of the cloud cover change with the Forbush decrease is established in the case of the auroral activity index АЕ > 300 nT and an anticorrelation in the case of a smaller Forbush decrease (for АЕ < 300 nT). Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 16–20, February, 2009.     

Contribution of flexural waves to the brittle fracture of dielectrics by dense pulsed electron beams

The nature of the natural acoustic modes which make the main contribution to the brittle fracture of thin dielectric plates by a pulsed electron beam 10⁻⁵–10⁻³ sec long is established. It is shown that these are flexural waves which arise directly due to nonuniform excitation of the sample. The amplitude of the dynamic tensile stresses in them is on average forty times greater than in the natural modes which arise as a result of the evolution of primary longitudinal thermoacoustic pulses in the reflection from the inner walls of the sample and the superposition of reflected longitudinal and transverse waves. Institute of High-Current Electronics, Siberian Section, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 68–81, November, 1997.     

Oxygen quenching of anthracene luminescence in geminate pairs

Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences, 3, Institutskaya Str., Novosibirsk, 630090, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 2, pp. 47–51, March–April, 1995.