The Experts below are selected from a list of 31482 Experts worldwide ranked by ideXlab platform
V.v. Syshchenko - One of the best experts on this subject based on the ideXlab platform.
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Coherent Radiation of electrons with ultrahigh energies in crystals
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1996Co-Authors: N. F. Shul'ga, V.i. Truten, V.v. SyshchenkoAbstract:Abstract Mechanisms of Coherent Radiation of electrons with ultrahigh energies in crystals are dealt with. Along with the conventional Coherent maxima new peaks in the Radiation spectrum are shown to appear at high energies. The appearance of these maxima is due to the contribution to the cross section from high index crystal planes. The conditions for the observation of the new peaks are discussed.
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Fine structure of the Coherent Radiation spectrum of ultrahigh energy electrons in a crystal
Physics Letters B, 1994Co-Authors: N. F. Shul'ga, V.i. Truten, V.v. SyshchenkoAbstract:Abstract A new maximum in the Coherent Radiation spectrum is predicted. It is related to the specific dynamics of ultrahigh energy electrons in crystals. It is shown that observing this effect in existing accelerators at energies ⩾100 GeV is feasible.
Solange B. Cavalcanti - One of the best experts on this subject based on the ideXlab platform.
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Non-Hermitian spectral changes in the scattering of partially Coherent Radiation by periodic structures
Optics Letters, 2019Co-Authors: Paulo A. Brandão, Solange B. CavalcantiAbstract:The physical aspects of partially Coherent Radiation interacting with deterministic non-Hermitian periodic materials remain largely unexplored in the statistical optics literature. Here, we consider the scattering of partially Coherent Radiation by a deterministic periodic medium, symmetric under the simultaneous transformations of parity inversion and time reversal, i.e., a parity–time-symmetric periodic medium. Taking into account light fluctuations, one is able to describe the spectrum changes on propagation and the influence of the coherence-driven angular divergence effect. The far-field spectral density profile is found to depend crucially on the loss/gain properties of the material, giving rise to unexpected and contrasting spectral diffraction profiles when compared to the Hermitian ones.
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Non-Hermitian spectral changes in the scattering of partially Coherent Radiation by periodic structures.
arXiv: Optics, 2019Co-Authors: Paulo A. Brandão, Solange B. CavalcantiAbstract:The physical aspects of partially Coherent Radiation interacting with deterministic non-Hermitian periodic materials remain largely unexplored in the statistical optics literature. Here, we consider the scattering of partially Coherent Radiation by a deterministic periodic medium, symmetric under the simultaneous transformations of parity inversion and time reversal, that is, a parity-time (PT)-symmetric periodic medium. Taking into account light fluctuations, one is able to describe the spectrum changes on propagation and the influence of the coherence-driven angular divergence effect. The far-field spectral density profile is found to depend crucially on the loss/gain properties of the material, giving rise to unexpected and contrasting spectral diffraction profiles when compared to the Hermitian ones.
Zugeng Wang - One of the best experts on this subject based on the ideXlab platform.
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Broadly tunable UV Coherent Radiation generated by two-step hybrid resonance four-wave mixing in Na2-Na mixture
Journal of Physics B: Atomic Molecular and Optical Physics, 1994Co-Authors: S L Deng, L J Qin, H Y Jin, X X Huang, Zugeng WangAbstract:By unequal-frequency hybrid resonance followed by hybrid resonance four-wave mixing in Na2-Na mixture, broadly tunable UV Coherent Radiation in the wavelength region 319.2-354.2 nm has been generated. The experimental and theoretical analysis have been focused on the particular mechanism and the features of the UV Coherent Radiation.
N. F. Shul'ga - One of the best experts on this subject based on the ideXlab platform.
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Simulating spectrum and polarization of Coherent Radiation by relativistic electrons in crystals
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1998Co-Authors: N. F. Shul'ga, A.a. Grynenko, V.i. TrutenAbstract:Abstract In the paper we attract attention to the fact that the inclusion of the actual dynamics of a particle moving inside a crystal at a small angle to one of its axes leads to a considerable distortion of spectrum and polarization characteristics of the Coherent Radiation obtained assuming the trajectory to be a straight line. It is essential that not only the Radiation intensity but also the interference pattern of the Radiation process undergo changes. That is important in quantitative analysis of measured data.
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Coherent Radiation under regular and chaotic motion of relativistic electrons and positrons in crystals
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1996Co-Authors: N. F. Shul'ga, V.i. TrutenAbstract:Abstract Coherent Radiation of relativistic electrons and positrons under regular and chaotic patterns of particle motion in a periodic field of atomic strings of a crystal is considered. The motion pattern has been shown to affect substantially the Coherent Radiation of particles in the crystal.
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Coherent Radiation of electrons with ultrahigh energies in crystals
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1996Co-Authors: N. F. Shul'ga, V.i. Truten, V.v. SyshchenkoAbstract:Abstract Mechanisms of Coherent Radiation of electrons with ultrahigh energies in crystals are dealt with. Along with the conventional Coherent maxima new peaks in the Radiation spectrum are shown to appear at high energies. The appearance of these maxima is due to the contribution to the cross section from high index crystal planes. The conditions for the observation of the new peaks are discussed.
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Fine structure of the Coherent Radiation spectrum of ultrahigh energy electrons in a crystal
Physics Letters B, 1994Co-Authors: N. F. Shul'ga, V.i. Truten, V.v. SyshchenkoAbstract:Abstract A new maximum in the Coherent Radiation spectrum is predicted. It is related to the specific dynamics of ultrahigh energy electrons in crystals. It is shown that observing this effect in existing accelerators at energies ⩾100 GeV is feasible.
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Dynamic chaos phenomenon and Coherent Radiation accompanying high energy particle motion through crystals
Radiation Effects and Defects in Solids, 1991Co-Authors: A.i. Akhiezer, V.i. Truten, N. F. Shul'gaAbstract:Abstract A crystal has a regular structure, therefore every motion in such a structure seems to be regular. However, it is not actually so and even in perfect crystals the particle motion may be either regular or chaotic. Everything depends on the number of integrals of motion determining a particle trajectory. The character of particle motion in a crystal, i.e. its regularity or chaoticity, affects many physical processes accompanying the particle motion through a crystal. In this paper we shall consider the effect of dynamic chaos on the Coherent Radiation of fast particles in a crystal. We also consider the validity conditions of Coherent Radiation theory results, the role of the second and higher Born approximations in the Radiation theory of fast particles in crystals, the continuous string approximation in this theory, the Coherent Radiation in the model of random strings, and the multiple scattering effect on the Coherent Radiation.
Paulo A. Brandão - One of the best experts on this subject based on the ideXlab platform.
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Non-Hermitian spectral changes in the scattering of partially Coherent Radiation by periodic structures
Optics Letters, 2019Co-Authors: Paulo A. Brandão, Solange B. CavalcantiAbstract:The physical aspects of partially Coherent Radiation interacting with deterministic non-Hermitian periodic materials remain largely unexplored in the statistical optics literature. Here, we consider the scattering of partially Coherent Radiation by a deterministic periodic medium, symmetric under the simultaneous transformations of parity inversion and time reversal, i.e., a parity–time-symmetric periodic medium. Taking into account light fluctuations, one is able to describe the spectrum changes on propagation and the influence of the coherence-driven angular divergence effect. The far-field spectral density profile is found to depend crucially on the loss/gain properties of the material, giving rise to unexpected and contrasting spectral diffraction profiles when compared to the Hermitian ones.
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Non-Hermitian spectral changes in the scattering of partially Coherent Radiation by periodic structures.
arXiv: Optics, 2019Co-Authors: Paulo A. Brandão, Solange B. CavalcantiAbstract:The physical aspects of partially Coherent Radiation interacting with deterministic non-Hermitian periodic materials remain largely unexplored in the statistical optics literature. Here, we consider the scattering of partially Coherent Radiation by a deterministic periodic medium, symmetric under the simultaneous transformations of parity inversion and time reversal, that is, a parity-time (PT)-symmetric periodic medium. Taking into account light fluctuations, one is able to describe the spectrum changes on propagation and the influence of the coherence-driven angular divergence effect. The far-field spectral density profile is found to depend crucially on the loss/gain properties of the material, giving rise to unexpected and contrasting spectral diffraction profiles when compared to the Hermitian ones.