Проведено исследование характеристики вторичного рентгеновского излучения, генерируемого в процессе работы стерилизатора на основе сильноточного импульсно-периодического ускорителя электронов СИНУС-320. Энергия ускоренных электронов составляет 500 кэВ. В связи с этим возникает необходимость радиационной защиты при эксплуатации установки, что, в свою очередь, приводит к важности изучения энергетического спектра и мощности дозы вторичного рентгеновского излучения. Исследования были проведены методом статистического моделирования с использованием программного пакета GEANT4. The work presents a study of the parameters of secondary X-ray radiation generated during the operation of a sterilization setup based on a high-current pulse-periodic electron accelerator SINUS-320. The energy of accelerated electrons equals 500 keV. Therefore, the issues of radiation protection during operation of the installation is highly topical, that leads to the importance of studying the energy spectrum and dose rate of secondary X-ray radiation. The studies were carried out by statistical simulation via GEANT4 toolkit.

The three components of the tensor analyzing power of the exclusive π– meson photoproduction reaction on deuterons measured simultaneously in the photon energy ranges 300–900 MeV and 50–210 MeV are presented. The experiment made use of an internal tensor-polarized deuterium-gas target of the VEPP-3 electron storage ring and the two-proton coincidence recording method. The results obtained are compared with theoretical predictions.

A (2+1)-dimensional Open image in new window gauge model is investigated. The presence of additional local U(1) symmetry, not associated with a physical gauge field, leads to the existence in the given model of two-dimensional non-vortex topological solitons carrying unquantized magnetic flux. Topological solitons of the given type were found numerically for fixed values of the model parameters. Analytical calculations of some properties of non-vortex topological solitons were performed. Universal dependences of the energy and magnetic flux of a non-vortex topological soliton on a dimensionless combination of parameters of the Open image in new window gauge model were obtained numerically. A comparative analysis of the properties of a non-vortex topological soliton and an Abrikosov–Nielsen–Olesen classical vortex is provided.

The currents of 5-ns pulsed high-current electron beams produced in a planar vacuum diode with explosive-emission cathodes made of various materials with no external magnetic field at an average electric field strength in the gap of about 300 kV/cm have been measured and time-integrated observation of the optical luminescence of the cathode surface have been performed. Cathodes with a ceramic bushing and spring metal contacts, with ceramic plates set in a magnetic iron matrix, with blades made of stamped exfoliated graphite (Graflex), with blades made of foil fiberglass plastic, and a composite cathode made of crystalline boron and copper powders were tested. The current carried by one emission center has been estimated to range between 5 and 20 A for various cathodes. For the metal-dielectric cathode, the velocity of expansion of the cathode plasma over the ceramic surface has been estimated as 2·10 7 cm/s. The lifetimes of the cathodes at a pulse repetition rate of 50 Hz have been investigated.

The effects of pulse-repetitive X-ray radiation and microwaves on the suspension of human erythrocyte was investigated in present work taking in to account changing their electrical capacitance. It was shown that the single 5-min exposure of suspension of erythrocyte to pulse periodic x-rays and microwaves causes the changes of the capacitance. The of the effect depends on the radiation type, the pulse repetition frequency, the radiation absorbed dose (in case of x-rays) and power flow density (in the case of microwaves).

We present the results of testing a new thermoacoustic sensor designed to detect microwave pulses having durations from 3 to 120 ns at wavelengths of 0.8 and 3 cm. Operation of the sensor is based on the effect of generation of acoustic signals during absorption of microwave pulses in a radiotransparent substrate–absorber–liquid layered structure . A thin nanometer-thick film deposited on a substrate is used as an absorber. Microwaves are converted to an acoustic pulse in the film and the adjacent liquid. The pulse is received by a wideband acoustic receiver and then recorded by a digital oscilloscope. It is shown that for a pulse duration of 120 ns, the shape of the signal recorded by the thermoacoustic sensor completely corresponds to the signal of a tube-diode detector of microwave pulses. The response of the thermoacoustic sensor to shorter pulses (3 and 5 ns long) is a pulse with a duration of 18 ns which is determined by a limited frequency band of the acoustic receiver.

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.

The effect of X-ray irradiation given in pulse-repetitive regimen on the proliferation of P-815 mastocytoma and Ehrlich carcinoma tumor cells was studied. The antiproliferative effect was found to depend on the pulse-repetitive frequency and sum absorbed dose of irradiation. Irradiation at an impulse frequency in a range 13-16 Hz is appeared to completely inhibit tumor cell proliferation despite on the fact that absorbed doses are some fold less than those used in radiotherapy for cancer. The ability of pulse-repetitive X-ray to inhibit tumor growth rate in mice was shown. Mechanisms of the action of pulsed X-ray irradiation are discussed.

The generation of short electromagnetic pulses excited in an extended slow-wave system (SWS) of a relativistic backward wave tube (BWT) operating in the so-called superradiance regime with a carrier frequency of 3.7 GHz has been simulated and experimentally studied. At a decreased magnetic field (about 0.2 T) in the SWS, the BWT generated 2.5-ns microwave pulses with a power of up to 800 MW. At a pulse repetition rate of 100 Hz, the working life of the system was limited by the lifetime of an explosive emission cathode (10(6) pulses). The possibility of phase synchronization of the high-frequency field of the relativistic microwave oscillator with respect to the voltage pulse front is demonstrated for the first time.