On the transition radiation and bremsstrahlung from a relativistic electron with a nonequilibrium field

The problem of the transition radiation from an electron with a nonequilibrium self-field appearing in view of the sharp scattering of the electron has been considered. It has been shown that the state of the electron with the nonequilibrium field is manifested in the suppression of transition radiation and in the oscillatory dependence of its characteristics on the distance from a plate on which radiation occurs to the scattering point. The problem of the measurement of the characteristics of bremsstrahlung under the conditions when macroscopic transverse distances are responsible for the scattering process has been considered. It has been shown that the results of the measurement in this case significantly depend on the size of the detector and on its position with respect to the scattering point.     

CH薄膜非平衡辐射烧蚀的特性

用一维多群辐射输运流体力学RDMG程序数值模拟研究了在神光-II黑腔辐射源条件下,非平衡辐射烧蚀CH薄膜的过程,给出了与平衡辐射烧蚀不同的烧蚀图像,得到了非平衡辐射烧蚀相关的数值定律。     

CH薄膜非平衡辐射烧蚀的特性

 用一维多群辐射输运流体力学RDMG程序数值模拟研究了在神光-II黑腔辐射源条件下，非平衡辐射烧蚀CH薄膜的过程，给出了与平衡辐射烧蚀不同的烧蚀图像，得到了非平衡辐射烧蚀相关的数值定律。     

Maser based on cyclotron resonance in a decaying plasma

The features of generating electromagnetic radiation in a two-level cyclotron maser whose active medium is a decaying nonequilibrium plasma confined in a magnetic field with the mirror configuration have been examined. It has been shown that, even in the absence of a continuously acting source of nonequilibrium particles (inversion of the medium), the system can exhibit the regimes of the quasimonochromatic or pulse generation of radiation owing to a fast monotonic decrease in the instability threshold that is characteristic of the plasma decay. The theory is confirmed by the results of observations of the burst activity of the decaying pulsed-discharge plasma under the conditions of the electron cyclotron resonance in the direct axisymmetric magnetic trap.     

Thermodynamics of nonequilibrium radiation. (II) Irreversible evolution and experimental setup

Giving continuation to the study of the thermodynamics of nonequilibrium radiation presented in the preceding article [Physica A 300 (2001) 386], we derive the evolution in time of its macroscopic nonequilibrium state. The case of a semiconductor sample and the coupling of radiation and transverse optical phonons is explicitly considered. Excitation of the latter drives the radiation field out of equilibrium. Under constant excitation, a steady state sets in which is analyzed. It is shown that the quasitemperature per mode of the radiation field, which has been defined in the preceding paper, can be determined in optical experiments such as Raman scattering.     

Amplification of electromagnetic radiation by a nonequilibrium plasma unstable against the development of Weibel instability

The reflection of an electromagnetic pulse by a nonequilibrium plasma in which the development of Weibel instability is possible has been studied. An exponentially strong amplification of the reflected signal at the stage of instability development has been found to be possible. The amplification maximum takes place at a radiation frequency comparable to the instability growth rate. A nonequilibrium plasma is shown to be a generator of radiation even after the switch-off of the incident pulse. The described effect of amplification of the reflected signal points, in particular, to a new possibility in mastering the terahertz frequency band.     

耦合辐射的三维热化学非平衡流数值模拟

发展耦合辐射的三维热化学非平衡流场计算方法,可用于非结构网格.采用Jameson有限体积法求解耦合辐射源项的三维N-S方程.辐射源项通过求解辐射输运方程(Radiative Transport Equation RTE)获得.在空间方向上离散后,采用有限体积法求解辐射输运方程.化学模型包含11个组元,20个化学反应.采用该数值方法计算MUSES-C模型在速度为11.6 km·s^-1时的绕流流场及前驻点处的辐射热流密度.并通过对比,分析热辐射对流场的影响.     

On the origin of nonequilibrium radiation from iodine molecules at the shock wave front

The direct simulation Monte Carlo (DSMC) method is used for modeling the problem on the shock wave front in the 0.7%I₂-99.3%He mixture for a shock wave Mach number of 4.85. The choice of this system is due to the fact that intense radiation peaks have been observed experimentally precisely in such systems and it has been convincingly proven that this effect is induced by high-energy collisions between I₂ molecules. The results of simulation provide additional sound arguments in favor of the conclusion that the translational nonequilibrium state at the shock wave front in a light gas with a small admixture of heavy nonreacting molecules may cause the experimentally observed nonequilibrium radiation peaks.     

On the problem of nucleation (cell formation) in self-organization of protein nanostructures <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">in vivo</Emphasis>

No convincing theory or hypothesis concerning the origin of biological cells exists today. Insight into the problem is difficult, because an empiric model of cell origination and division at the crucial phase of life, self-organization of protein nanostructures, is lacking. It has been shown experimentally that protein nanostructures exhibit signs of self-organization when an open far-from-equilibrium protein-water system condenses in vitro. In other words, to be active, protein must be in the nonequilibrium state. Such a form of self-organization is accompanied by nucleation and the formation of defects, which divide the protein film into domains (“cells”) with nuclei. This type of structuring in the nonequilibrium (active) protein may be viewed as a crude empiric model of protein nucleation, since it includes the formation and division (self-organization) of biological cells, the origination of which, in turn, is intimately related to the self-organization of protein at the nanolevel. The reason for the similarity of the basic processes is identical conditions of protein condensation in vitro and in vivo. In both cases, when water evaporates rapidly from an open water-protein system that is far from thermodynamic equilibrium, the conditions necessary for protein nonequilibrium nanostructures be self-organized with nucleation in the form of nucleus-containing “cells” are set.     

Investigation of various operation modes of a miniature superconducting detector of microwave radiation

Nonequilibrium electron and phonon distribution functions have been calculated for a metallic absorber of a promising miniature superconducting detector irradiated by microwave radiation. The response of this detector has been calculated, and it has been shown that this detector can operate in either the photon counter mode or bolometric mode in dependence on the degree of nonequilibrium of the phonon subsystem.     

Magnetization and diamagnetism of a longitudinal autosoliton in <Emphasis Type="Italic">p</Emphasis>-InSb in an external longitudinal magnetic field

It has been experimentally shown that a longitudinal thermal-diffusion autosoliton, which is generated in a nonequilibrium electron–hole plasma in p-InSb, in an external longitudinal magnetic field acquires diamagnetic properties. The results of the calculation and numerical estimates of the diamagnetism have been presented.     

Thermal Conductivity of Three‐Dimensional Yukawa Liquids (Dusty Plasmas)

An improved method is proposed to investigate the behavior of a Yukawa liquid under the action of an external field strength using computer simulated nonequilibrium molecular dynamics. The thermal conductivity calculations with appropriate normalizations, in the limit of low value field strengths, are estimated over a wide range of the Coulomb coupling and screening strengths. The new simulations provide more reliable data for the thermal conductivity than the previously known results for the Yukawa liquids. The calculations show that the thermal conductivity is dependent on both the Coulomb coupling and screening parameters in the three‐dimensional (3D) Yukawa liquids. The low value field strength simulation data are found to obey the universal and quasiuniversal scaling. It is shown that the homogenous nonequilibrium method can be used to predict the thermal conductivity in Yukawa systems and to understand the fundamental features of 3D dusty plasma liquids (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Nonequilibrium processes at the shock wave front in inert gases with a small amount of Fe(CO)<Subscript>5</Subscript> impurity

Nonequilibrium processes occurring in shock waves generated in argon and helium containing a small amount of Fe(CO)₅ impurity are investigated experimentally and numerically. Nonequilibrium radiation peaks are found in the relaxation zone of the shock wave, and a dependence of the radiation intensity on the shock parameters and Fe(CO)₅ concentration is obtained. Unresolved spectra of the resulting radiation in the range 400–700 nm are recorded. It is shown that the effects observed cannot be accounted for by high-energy collisions in the zone of shock translational relaxation. It is concluded that these nonequilibrium phenomena are related to electronic excitation of small iron clusters at fast condensation of supersaturated iron vapor arising due to Fe(CO)₅ decomposition. A kinetic model describing the formation of excited clusters is suggested.     

Direct interaction,classical thermodynamic and quantum statistical theories of heavy ion collisions

Various theories of composite-particle formation are developed and compared. One theory is a nonequilibrium final-state interaction model, while another theory is based on equilibrium thermodynamics. A version of the equilibrium model is developed which is classical - analogous to the Rayleigh-Jeans limit of black-body radiation. Recent experiments suggest that the nonclassical equilibrium predictions are in better agreement with data than the results of the nonequilibrium picture or the classical thermodynamic view.     

Field-swept magnetization hysteresis of magnetic V<Subscript>15</Subscript> nanoclusters

The mechanism of hysteresis of magnetization in superparamagnetic systems under a time-increasing (decreasing) magnetic field is studied. The model used involves the nonequilibrium thermodynamic properties of superparamagnetic systems, such as the difference in temperature between the spin subsystem and the lattice caused by a sweeping magnetic field. It is shown that the temperature of the spin system and, hence, the magnitude of the magnetization always lag behind a variable magnetic field, which might be the cause of the observed hystertesis of magnetization. The results of calculations are compared with the experimental data for V₁₅ nanoclusters.     

Coplanar three-beam X-ray diffraction study in TeO<Subscript>2</Subscript> single crystal using synchrotron radiation

The results of the first experimental study of coplanar three-beam X-ray diffraction in a paratellurite (TeO₂) single crystal using synchrotron radiation on a Kurchatov synchrotron radiation source are presented. Four cases with (220, 371), (220, 464), (220, 370), and (110, 557) indices have been investigated. In all cases the change of the rocking curve shape of the weak reflection has been observed due to the multibeam interaction resulting in the appearance of two peaks in the reflection curve corresponding to two scattering mechanisms: amplitude and resonance. The origin of the insufficient resolution in the experiments has been considered. It has been shown that the obtained data correspond to the results of the computer simulation.     

Simulation of the current induced by 63Ni beta radiation

The current generated by radiation from a ⁶³Ni layer of variable thickness is simulated with the actual spectrum of emitted electrons and with their distribution over the angles for Si and SiC taken into account. The dependences of the generation rate for nonequilibrium charge carriers on the depth are obtained for the cases of several Ni film thicknesses for both materials. The results are compared with the simulation results for a monoenergetic electron beam that is perpendicular to a semiconductor detector. It is shown that, for both Si and SiC, it is possible to choose an energy value of the electron beam in a SEM such that the ratio of the currents induced by the SEM beam and beta radiation from ⁶³Ni is essentially independent of the diffusion length.     

Theory of a stationary microwave discharge with multiply charged ions in an expanding gas jet

The formation of a jet of a nonequilibrium multiply charged ion plasma is studied in the inhomogeneous gas jet. It is shown that the geometrical divergence of the jet restricts the maximum ion charge state and results in the spatial localization of the discharge. Stationary solutions corresponding to such regimes are constructed. The model proposed can be used to optimize modern experiments on generation of hard UV radiation due to the line emission of multiply ionized atoms in a gas jet heated by high-power millimeter and submillimeter radiation.     

Absolute negative resistance in a nonequilibrium two-dimensional electron system in a strong magnetic field

The effect of microwave electromagnetic radiation on the resistance of the 2D electron gas in a GaAs/AlAs heterostructure in a strong magnetic field is investigated. It is shown that, under the nonequilibrium conditions caused by microwave radiation, the aforementioned 2D system exhibits giant oscillations of its resistance with varying magnetic field. When the measuring current density is small, an increase in the microwave power leads to the appearance of an absolute negative resistance at the main minimum of these oscillations, which lies near the cyclotron resonance. The experimental data are found to be in qualitative agreement with the theory of multiphoton photoinduced impurity scattering [J. Inarrea and G. Platero, Appl. Phys. Lett. 89, 052109 (2006)].