Energy Characteristics Of Radiation Research Articles

Study of the effects of ultra-low intensity electromagnetic fields on biological objects

The object of research is the efficiency of exposure to electromagnetic field (EMF) of ultra-low intensity on biological objects, which is formed by a generator of broadband radiation. The principle of action of the generator is based on formation of electromagnetic radiation induced by periodic pulsed gas discharge in coaxial system of electrodes, which is loaded on a dielectric rod antenna. The method of selection of signals and corresponding equipment, which energy characteristics of radiation correspond to the criterion of non-thermal influence on bioobjects, is developed for obtaining a comparative assessment of influence bioefficiency. The proposed new method for processing experimental data using statistical calculations that meet the requirements for the processing and interpretation of the results. The seeds of wheat and interaction of millimeter range electromagnetic oscillations with bone marrow cells of rats were used as biological objects for investigating the effect of millimeter range electromagnetic oscillations. A biosensory effect was obtained when exposed to broadband radiation of ultra-low intensity, compared to the control sample. A change in the properties of the seeds, in particular, heat resistance, is observed. According to the experimental data, seeds turn out to be less susceptible to heat as a result of their pretreatment with EMF. The biological response is observed to depend on the frequency and time of irradiation. Also, the dependence of the decrease in the number of dead cells on the time of EMF irradiation was experimentally proved. The equation of dependence of selective average proportion of dead cells in rat bone marrow on irradiation time was calculated. Biosensory effect of exposure to broadband ultra-low intensity EMF of the developed emitter was revealed. It was established and statistically proved that the minimum time with the maximum positive effect of exposure to electromagnetic radiation of millimeter range on bone marrow cells of rats is 30 minutes, compared with an unirradiated sample. The results make it possible to evaluate the positive effect of electromagnetic oscillations on biological objects and propose the results of studies for practical use in the development of medical systems.

Configuration Model of a Grating Pair Pulse Compressor

This paper proposes the unifying model that describes configuration of a wide-aperture laser compressor formed by pairs of parallel diffraction gratings. The model couples eight independent parameters of broadband laser radiation, diffraction gratings, and pulse compressor configuration. A new analytical method to describe delays in a wide-aperture beam propagating through a system of several grating pairs is proposed based on separate analysis of monochromatic and wavelength-dependent delays. Model-based optimization can be applied to spectral, phase, temporal, spatial, and energy characteristics of radiation at the output of a high-power laser facility. It is shown that the model allows minimizing the required size of diffraction gratings and increasing the cross section of the light beam at the output of a Nd-glass laser facility. A new multi-paired architecture of the compressor is described.

Plasma Radiation Source on the Basis of the Gas Puff with Outer Plasma Shell in the Circuit of a Mega-Ampere Load Current Doubler

Characteristics of Z-pinch plasma radiation in the form of a double shell neon gas puff with outer plasma shell are investigated in the microsecond implosion mode. Experiments are performed using a GIT-12 mega-joule generator with load current doubler having a ferromagnetic core at implosion currents up to 5 MA. Conditions for matching of the nonlinear load with the mega-ampere current multiplier circuit are determined. The load parameters (plasma shell characteristics and mass and geometry of gas puff shells) are optimized on the energy supplied to the gas puff and n energy characteristics of radiation. It is established that the best modes of K-shell radiation in neon are realized for such radial distribution of the gas-puff material at which the compression velocity of the shell is close to a constant and amounts to 27–30 cm/μs. In these modes, up to 40% of energy supplied to the gas puff is converted into K-shell radiation. The reasons limiting the efficiency of the radiation source with increasing implosion current are analyzed. A modernized version of the energy supply from the current doubler to the Z-pinch is proposed.

Optical Characteristics of a Gas Discharge Plasma Based on a Mixture of Mercury Diiodide Vapor, Nitrogen, and Helium

The results of studies of spectral, temporal, and energy characteristics of radiation in a gas discharge plasma based on a mixture of mercury diiodide vapor with helium and nitrogen in the spectral range of 350–800 nm are presented. Plasma was produced by a barrier discharge in a device with a cylindrical aperture. The electrodes 0.2 m in length were placed at a distance of 0.015 m. The amplitude of the pump pulses, their duration, and frequency were equal to 20–30 kV, 150 ns, and 1–20 kHz, respectively. Radiation of mercury monoiodide exciplex molecules was revealed in the visible spectra region. Dependences of the plasma optical characteristics on the partial pressures of the mixture components were established.

Controlling the radiation characteristics of a magnetically compressed discharge of megawatt electric power

For a plasma light source based on a magnetically compressed discharge operating in a regime with a discharge-current pulse width equal to 1 s, induced by an electric power of about 1 MW, the possibilities are investigated of forming the time dependence and energy characteristics of radiation supplied from a network thyristor rectifier with an output voltage of about 500 V and a discharge current of up to 6000 A. It is shown that increasing the fraction of easily ionizable elements (Na, Ca, La) in the composition of the plasma-forming material increases the radiant exitance of the plasma radiator. The optimum induction of the compressing magnetic field is found.

Energy characteristics of radiation of law-temperature plasma based on mixtures of mercury dibromide vapor with gases

The results of studies of energy characteristics of radiation of low-temperature plasma in mixtures of mercury dibromide vapor with nitrogen, sulfur hexafluoride and helium are presented. Creation of plasma was carried out in a cylindrical device with a volume of ~ 1 cm 3 by a barrier discharge with a pulse - periodic voltage form with the duration and repetition rate of 400-600 ns and 3-9 kHz, respectively. The conditions of mercury monobromide exciplexes formation and emission are revealed. It is established that the highest average and pulse output power is achieving in a HgBr 2 -SF 6 -N 2 -He mixture, and the values in a self-heating mixture mode are 48.8 mW and 40.6 W respectively at an efficiency ≤10 %.

Energy characteristics of radiation from a KULON-10 Cu-M self-heated technological laser

The energy characteristics of a KULON-10 Cu-M technological copper vapour laser operating in the regime of high-speed pulsed modulation produced by special current pulses are investigated. The range of time delays of an additional pulse with respect to the main pulse is determined in which the peak power of laser pulses, their energy and duration can be varied. The total all-line peak power of the laser within the total divergence angle achieves 120 kW for the nominal delay. The average and peak powers, energies, and durations of pulses are measured for the individual components of the laser beam with different divergence (down to diffraction-limited). It is shown for the first time that the fraction of the pulse energy corresponding to the weakly diverging component of the laser beam and the laser pulse duration decrease with decreasing the time delay (below the nominal value). The outlook for using KULON lasers for nonlinear radiation frequency conversion is estimated.

Consecutive Q-switched self-frequency conversion in periodically poled active nonlinear crystals

The results of theoretical studies of consecutive processes of self-frequency conversion in a Q-switched regime are presented. A scheme consisting of a periodically poled active nonlinear crystal and modulator located in the cavity is analyzed. The time dynamics and energy characteristics of radiation at consecutive processes of self-frequency tripling and parametric self-frequency conversion are calculated using numerical methods. Parameters of cavity, pump, and Q switching corresponding to maximum powers of radiation are found.

Energy characteristics of radiation from an oscillating dipole moving in a dielectric medium with resonant dispersion

Radiation produced by oscillations of an electric dipole moving along its dipole moment through an insulator with the resonance-type dispersion is considered. The total power of radiation and the power density spectrum are studied both analytically and numerically. It is shown that the radiation spectrum consists of either two separate frequency ranges or a single frequency range depending on the parameters of the problem. The dependences of the radiation power on the velocity of the source are revealed for various values of the resonant and Langmuir frequencies.

Time and Energy Characteristics of Radiation at Q-switched Self-Frequency Conversion

The results of a theoretical study of quasi-phase matched processes at self-frequency conversion in the Q-switched regime are presented. A scheme containing a periodically poled active nonlinear crystal and an acousto-optical modulator inserted inside the cavity is considered. Solutions of the set of equations describing such scheme are obtained by numerical methods. The time dynamics of the self-frequency doubling, self-frequency summing, and self-parametric frequency conversion processes are studied in detail. The energy characteristics of the radiation are also calculated and compared with those in the stationary regime.

Energy characteristics of radiation of oscillating dipoles moving in a nondispersive medium and a cold plasma

We consider radiation of moving oscillating electric and magnetic dipoles, whose moments are oriented along their velocity. We have derived general expressions for field components and radiation power, which are valid for isotropic homogeneous nonabsorbing media. Special cases of a nondispersive medium and a cold plasma are considered. In these cases, the dependences of energy spectral distributions and radiation powers are analyzed as a function of the velocity of the sources and the parameters of media.

Study of the radiation divergence and energy efficiency of a pulsed Nd3+ : YAG laser transversely pumped by laser diode arrays

The spatial and energy characteristics of radiation from a pulsed Nd3+ : YAG laser transversely pumped by laser diode arrays are studied experimentally by varying the resonator parameters. The differential efficiencies of the laser for multimode and close to single-mode free running lasing were measured to be 48 % and 40 % — 42 %, respectively.

Intermediate regime for the diffraction of light by ultrasound in cubic crystals with electrically induced anisotropy

The energy characteristics of radiation transmitted by a polarizer?acoustoelectrooptic-cell system based on a cubic crystal analyzer is analyzed in the four-wave approximation. A basis is provided for the possibility of modulating light by varying the acoustic power, the controlling electric field, and the polarization of the incident electromagnetic wave. This can be of interest when creating multichannel modulators of optical radiation.

Conditions for Obtaining Stimulated Radiation in Thin‐Film Organic Electroluminescent Structures

This paper analyzes the possibilities of obtaining induced radiation in single‐layer organic electroluminescent structures on the basis of the proposed model of luminophor molecule excitation by “hot” electrons emitted from the cathode as a result of the tunnel effect. Numerical calculations of the kinetic, spectral, and energy characteristics of radiation in the regime of single‐pass superluminescence and in the presence of positive feedback have been made. It has been concluded that, in principle, it is possible to obtain in such systems induced radiation at actually attainable values of the applied electric‐field strength, and the conditions for this have been analyzed.

Contour Hologram Recording under the Formation of Multifrequency Pulsed Radiation Using Stimulated Brillouin Scattering

A ruby light source is described that emits a giant multifrequency pulse, in which each spectral line, except for the initiating radiation line, is a Stokes component of the stimulated Brillouin scattering of the preceding adjacent line. The results of experimental studies of the temporal, spectral, and energy characteristics of radiation are presented. It is shown that the radiation formed can be used for the holographic recording of contour maps with a narrower fringe than that obtained with a two-frequency laser.

Synchrotron Radiation in a Circular Metallic Waveguide

We study theoretically the influence of a circular metallic waveguide with a longitudinal magnetic field on the synchrotron radiation of a point electric charge moving along a helical trajectory coaxial with the waveguide axis. The main attention is focused on the analysis of the energy characteristics of radiation of electromagnetic E and H waves. We derive the formulas for the radiation powers of E and H waves. It is shown that, under certain conditions, slowly moving electric charges do not radiate any of these electromagnetic waves in the circular waveguide.

Effect of an aerosol on the spectral and energy characteristics of radiation from the earth's surface, tropospheric clouds, and the atmosphere observed from space in the range 1-3mm

Effect of an aerosol on the spectral and energy characteristics of radiation from the earth's surface, tropospheric clouds, and the atmosphere observed from space in the range 1-3mm

High-energy laser with passive mode locking and a resonatorQfactor dynamically controlled by negative feedback

A high-energy YAG:Nd laser system capable of generating long (up to 2500 pulses) trains of picosecond pulses of controlled duration was built. The total energy of the output radiation consisting of a train of about 1500 pulses was constant at ~ 5.3 mJ and the energy of a single pulse was 3.5 μJ. These values were 20 times better than the energy characteristics of radiation from a laser with a negative feedback loop and over 40 times better than those of a cw YAG:Nd laser with mode locking.

Spectral and energy characteristics of radiation from an electron-beam-controlled13C16O2laser

An experimental investigation was made of the energy and spectral characteristics of radiation from an electron-beam-controlled 13C16O2 laser under quasi-cw conditions. The composition of the active mixture and the pump pulse duration were varied.