Self-consistent renormalized phonons in metallic and nonmetallic solids

The interaction of charged particle beam with non-linear “cubic” type media has been studied; the dielectric permeability of such media depends on the square strength of the electric field produced by the beam-excited wave. The processes of the Cherenkov excitation of the medium by a modulated definite current are investigated as well as the polarization of longitudinal oscillations of the medium excited by the current. The equations are obtained to determine the dependence of fields excited by the current on the amplitude of the exciting current. It is found that under certain circumstances (near the radiation cut-off) the conditions of Cherenkov radiation may be violated due to non-linearities of the medium and the particle radiation loss vanish. The amplification of longitudinal waves in an arbitrary isotropic medium with “cubic” non-linearity by a monoenergetic particle beam is studied when the frequencies of amplified oscillations are close to the resonance frequencies of the medium.     

Excitation of a wake field by a relativistic electron bunch in a semi-infinite dielectric waveguide

A wake field excited by a relativistic electron bunch in a semi-infinite metal waveguide filled with a dielectric consists of the Vavilov-Cherenkov radiation, the “quenching”-wave field, and transient radiation, which interfere with each other. An exact analytic expression for the transient component of the field of a thin relativistic annular bunch is derived for the first time. The evolution of the space distribution of a field excited by a finite-size electron bunch is numerically calculated. The excitation of the wake field by a periodic train of electron bunches in a finite-length waveguide is studied.     

Molecular Spectroscopy with Coherent Radiation Sources

Various characteristics of molecules have been clarified by spectroscopic methods in which the interactions of molecules with the radiation field were investigated. A stationary response of a molecule excited by a radiation field appears as a spectral line. Information on molecules may be obtained from position (resonance frequency), intensity, and shape and width of the spectral line. So far the interaction of molecules with the radiation field has been studied primarily in a “frequency domain.” Although molecular spectroscopy is one of the research fields in modern science which has the longest history, a variety of important aspects have been demonstrated very recently in this field as radiation sources have been improved. When the radiation field is “weak,” the photon nature of the radiation field is dominant in the interaction with a molecule, such as in the cases of emission, absorption, and scattering of photons. When the radiation field is “strong,” in the sense that many photons exist in a proper mode of the radiation field, the wave nature of the field plays an important role in the interaction. In this case the radiation may be described in the form of the classical field, say, a sinusoidal function of the time and spatial coordinates, coherently interacting with the molecule, which is described quantum mechanically. Here nonlinear properties would appear in the interactions: saturation in absorption, induced scattering, multiphoton processes, coherent transients, etc.     

Kinetic effects in an optically excited gas

A resonance transition in a one-dimensional layer of gas contained between transparent parallel plates and optically excited by external radiation has been treated using kinetic theory. A perturbation method has been used to obtain the “first scattering” results for the velocity distribution and number density of excited atoms and the intensity of radiation at any point in the gas. Two special cases are discussed in detail: broad band excitation with inhomogeneous broadening and monochromatic excitation with homogeneous broadening. The effects of particle streaming and wall quenching are shown to produce boundary layer behavior in the excited level density which scales with the particle mean free path. In addition, line reversal of the radiation reemited from the gas is shown to occur and to be a direct result of particle streaming. Numerical and asymptotic results are presented which show these effects. These results should be pertinent to many laboratory and industrial devices in which the particle and photon mean free paths are comparable and to diagnostic techniques which use resonance fluorescence to infer excited level densities.     

Sound radiation from point-excited structures: Comparison of plate and sphere

Acoustic radiation from a structure can be expressed in terms of “modal radiation” and “modal coefficients”. This paper investigates the contributions of these two modal properties to radiation excited by a point force. Sound radiation from two basic structures is considered: a baffled rectangular plate and a closed spherical shell. The plate behaviour is familiar, and governed by the relation between the natural frequency of a mode and its coincidence frequency. For a closed spherical shell, there are either zero or two “critical frequencies”, depending on the radius and thickness. When there are two the shell radiates well both above and below the two frequencies, and poorly in the frequency range between them.     

Angle-resolved polarization-dependent photoemission from Cu(100) and Cu(111): experiment and theory

Experimental angle-resolved photoemission spectra from Cu(111) and Cu(001) excited by linearly polarized light (21.2 eV) are compared with intensity results calculated by the “one step model” theory. Good overall agreement is obtained both for s- and p-polarized light assuming a classical macroscopic radiation field inside the crystal.     

Resonant field amplification near the RWM stability boundary in a tokamak

Evolution of a resistive wall mode (RWM)—a magnetic field perturbation produced by a plasma and partially stabilized by a conducting wall—is considered. It is assumed that there is a small resonant harmonic in the spectrum of the static error field. It is shown that the effect of this harmonic on the dynamics of stable RWMs increases as the plasma approaches the RWM stability boundary. The error field is “amplified” during the transition through this boundary. The smaller the rotation velocity of the perturbation and the longer the time during which the plasma stays near the stability boundary, the stronger this amplification is.     

Migration of excitation in transfer of spectral-line radiation

A simple mathematical model is developed for the transfer of energy through a gas by the combined effect of radiative transfer and migration of excitation. The “excitation” is carried through the gas by a succession of atoms which experience resonant excitation exchange; it thus appears to random walk through the medium. The theory developed here is valid when the distance traveled by an atom while excited is much larger than the typical distance at which two atoms can exchange excitation (roughly 10^-6cm). The model is expressed in terms of a pair of coupled transport equations for the intensity of radiation and the density of excited atoms, which are solved by means of a generalized discrete-ordinate technique. Extensive numerical results are obtained and discussed in terms of characteristics lengths for the various transfer processes. Substantial effects of migration are seen in both the distribution of excited atoms near the cell windows and the line profile of the emergent radiation for typical laboratory conditions.     

Self field electromagnetism and quantum phenomena

Abstract

Quantum Electrodynamics (QED) has been extremely successful inits predictive capability for atomic phenomena. Thus the greatest hope for any alternative view is solely to mimic the predictive capability of quantum mechanics (QM), and perhaps its usefulness will lie in gaining a better understanding of microscopic phenomena. Many “paradoxes” and problematic situations emerge in QED. To combat the QED problems, the field of Stochastics Electrodynamics (SE) emerged, wherein a random “zero point radiation” is assumed to fill all of space in an attmept to explain quantum phenomena, without some of the paradoxical concerns. SE, however, has greater failings. One is that the electromagnetic field energy must be infinit eto work. We have examined a deterministic side branch of SE, “self field” electrodynamics, which may overcome the probelms of SE. Self field electrodynamics (SFE) utilizes the chaotic nature of electromagnetic emissions, as charges lose energy near atomic dimensions, to try to understand and mimic quantum phenomena. These fields and charges can “interact with themselves” in a non-linear fashion, and may thereby explain many quantum phenomena from a semi-classical viewpoint. Referred to as self fields, they have gone by other names in the literature: “evanesccent radiation”, “virtual photons”, and “vacuum fluctuations”. Using self fields, we discuss the uncertainty principles, the Casimir effects, and the black-body radiation spectrum, diffraction and interference effects, Schrodinger's equation, Planck's constant, and the nature of the electron and how they might be understood in the present framework. No new theory could ever replace QED. The self field view (if correct) would, at best, only serve to provide some understanding of the processes by which strange quantum phenomena occur at the atomic level. We discuss possible areas where experiments might be employed to test SFE, and areas where future work may lie.     

Boundary energy and boundary states in integrable quantum field theories

We study the ground-state energy of integrable 1 + 1 quantum field theories with boundaries (the genuine Casimir effect). In the scalar case, this is done by introducing a new “R-channel TBA”, where the boundary is represented by a boundary state, and the thermodynamics involves evaluating scalar products of boundary states with all the states of the theory. In the non-scalar, sine-Gordon case, this is done by generalizing the method of Destri and De Vega. The two approaches are compared. Miscellaneous other results are obtained, in particular formulas for the overall normalization and scalar products of boundary states, exact partition functions for the critical Ising model in a boundary magnetic field, and also results for the energy, excited states and boundary S-matrix of O(n) and minimal models.     

Sound transmission at low frequencies through the walls of distorted circular ducts

A theoretical treatment of sound transmission through the walls of distorted circular ducts is given, for plane mode transmission within the duct. The transmission mechanism is essentially that of “mode coupling”, whereby higher structural modes in the duct walls are excited, because of the wall distortion, by the internal sound field. The theory is in two parts: an approximate analytical model for the structural response of the walls to the internal sound field, and a structural radiation model. Computed results, based on the theory, are compared to measurements on “long-seam” air conditioning ducts. Where the duct geometry can be reliably specified, reasonably good agreement is obtained between theoretical and experimental data. It is concluded that mode coupling effects serve to account for the discrepancies between ideal and observed behaviour in sound transmission through duct walls.     

Casimir Effect and Black Hole Radiation

The gravitational field of a black hole intrinsically creates a potential barrier consisted of two reflecting boundaries; the first one far from the hole and the second one in the vicinity of its horizon. With respect to this fact and assuming the boundaries as good conductors (in view of an observer near the horizon just outside the second boundary), in a series of papers, R.M. Nugayev by considering a conformally coupled massless scalar field and based on the calculations of Candelas and Deutsch (the accelerated-mirror results) has claimed that “...the existence of the potential barrier is as crucial for Hawking evaporation as the existence of the horizon”. In this paper, by taking the same assumptions, through straightforward reasonings, we explicitly show that contrary to this claim, the effects of the first boundary on the black hole radiation are quite negligible. Moreover, the inclusion of the second boundary makes the situation more complicated, because the induced Casimir energy-momentum tensor by this boundary in its vicinity is divergent of order \(\delta ^{-4}\) (δ is the distance to the boundary).     

利用运动光束抑制高功率激光小尺度自聚焦

提出了近场“运动光束”的概念.指出光谱色散匀滑装置可以在近场产生运动光束,理论分析了运动光束的产生机理、条件、运动特性以及对小尺度自聚焦的抑制作用.通过数值模拟,得到计算结果与理论分析一致. 关键词： 运动光束 光谱色散匀滑 小尺度自聚焦 惯性约束聚变     

Meeting Reports: 2005 Annual Meeting of JSSRR (Japanese Society for Synchrotron Radiation Research)

The 18th Annual Meeting and General Assembly of the Japanese Society for Synchrotron Radiation Research (JSSRR) and the joint symposium of synchrotron radiation facility user's society groups were held at Sun-Messe Tosu Conference Hall in Tosu City, Japan, from January 7 to 9, 2005. The meeting was attended by 607 people and included 6 symposiums, 96 oral presentations, and 356 poster presentations covering all aspects of synchrotron radiation research and technology. The meeting also included 49 industrial exhibitions.

The six symposiums were on “Recent progress on soft X-ray optical elements,” “Now and the future on SR-XRF analysis for biological and environmental sciences,” “Recent development of THz Coherent Synchrotron Radiation,” “Super high-resolution protein structure analysis,” “Frontlines of Bio-Nano-microspectroscopy by UV-SX high brilliance SR,” and “The role of synchrotron radiation in the future of science: groundbreaking SR utilization for research on excited states”.     

Coexistence of collective and single-particle effects in the photoresponse of a 2D electron gas to microwave radiation

The photoresponse of magnetoresistance of a high-density two-dimensional electron system to microwave electromagnetic radiation is studied. The damping of the Shubnikov-de Haas oscillation by radiation with a non-monotonic dependence of this effect on the magnetic field and the radiation-induced oscillations of magnetoresistance are observed. The damping is most pronounced within isolated narrow magnetic field intervals that closely correspond to the expected positions of magnetoplasma resonances in the sample under study and also near the cyclotron resonance position. A “window” is observed in the photoresponse near the field value predicted on the basis of a single-particle electron spectrum consisting of broadened Landau levels. The radiation-induced oscillations, the window in the photoresponse, and the damping of the Shubnikov-de Haas oscillations near the cyclotron resonance are described in terms of the theory based on the concept of the nonequilibrium filling of single-electron states. Thus, it is demonstrated that the photoresponse pattern observed in the experiment is formed by both single-particle and collective (magnetoplasma) effects.     

Acoustic streaming in a sound field near a free boundary

Stationary acoustic streaming that occurs near the free boundary of a compressible viscous liquid in the field of a standing sound wave excited along this boundary is theoretically investigated.     

Exact partition function and boundary state of 2D massive Ising field theory with boundary magnetic field

We compute the exact partition function, the universal ground-state degeneracy and boundary state of the 2D Ising model with boundary magnetic field at off-critical temperatures. The model has a domain that exhibits states localized near the boundaries. We study this domain of boundary bound state and derive exact expressions for the “g function” and boundary state for all temperatures and boundary magnetic fields. In the massless limit we recover the boundary renormalization group flow between the conformally invariant free and fixed boundary conditions.     

Theory of Gravitational-Inertial Field of Universe

In this paper the basic proposition is a generalization of the metric tensor by introduction of an inertial field tensor satisfying ?_ig_lm ? g_lm;i ≠ 0. On the basis of variational equations a system of more general covariant equations of gravitational-inertial field is obtained. In Einstein's approximation these equations reduce to the field equations of Einstein. The solution of fundamental problems of generl taheory of relativity by means of the new equations give the same results as Einstein's equations. However application of these equations to the cosmologic problem leads to following results: 1. All Galaxies in the Universe (actually all bodies if gravitational attraction is not considered) “disperse” from each other according to Hubble's law. Thus contrary to Friedmann's theory (according to which the “expansion of Universe” began from the singular state with an infinite velocity) the velocity of “dispersion” of bodies begins from the zero value and in the limit tends to the velocity of light. 2. The “dispertion” of bodies represents a free motion in the inertial field and Hubble's law represents a law of motion of free bodies in the inertial field - the law of inertia. All critical systems (with Schwarzschild radius) are specific because they exist in maximal inertial and gravitational potentials. The Universe represents a critical system, it exists under the Schwarzschild radius. In the high-potential inertial and gravitational fields the material mass in a static state or in the process of motion with decelleration is subject to an inertial and gravitational “annihilation”. Under the maximal value of inertial and gravitational potentials (= c²) the material mass is completely “evaporated” transforming into a radiation mass. The latter is concentrated in the “horizon” of the critical system. All critical systems –“black holes”- represent geon systems, i.e., the local formations of gravitational-electromagnetic radiations, held together by their own gravitational and inertial fields. The Universe, being a critical system, is “wrapped” in a geon crown. The Universe is in a state of dynamical equilibrium. Near the external part of its boundary surface a transformation of matter into electromagnetic-gravitational-neutrineal energy (geon mass) takes place. Inside the Universe, in the galaxies takes place the synthesis of matter from geon mass, penetrating from the external part of the world (from geon crown) by means of a tunneling mechanism. The geon system may be considered as a natural entire cybernetic system.     

Flat coordinates of topological conformal field theory and solutions of the Gauss–Manin system

A luminescent trace has been observed in a ruby crystal (Al₂O₃: Cr³⁺) that rotates at a frequency of 2 to 200 Hz and is irradiated by 532-nm coherent electromagnetic radiation. A method has been proposed to determine the lifetime of the excited electronic state of chromium ions from the measurement of the length of an arc of the trajectory of a light spot on the surface of a rotating ruby single crystal. A “comet trace” formed at the passage of radiation through the rotating crystal near the absorption band of the material has been detected inside the ruby crystal. It has been shown that the theory based on the analysis of the motion of polaritons in the rotating reference frame is in satisfactory agreement with experimental results.     

“禁戒光”近场光学显微镜原理与系统

扫描近场光学显微术是８０年代后期发展起来的一种分辨率超过衍射极限的新型光学显微镜技术。本文介绍了国外最近出现的“禁戒光”近场光学显微镜系统的工作原理及结构。透射式ＳＮＯＭ中部分光沿着光轴向前传播；部分光沿着大于全内反射临界角的方向传播。前者称为允许光；后者称为禁戒光。应用“禁戒光”近场光学显微镜可同时获得三幅图像，即允许光像、禁戒光像和反映样品表面形貌的剪切力图像。禁戒光图像能够提供很好的对比度和分辨率。