scholarly journals Theory of Cherenkov radiation in periodic dielectric media: Emission spectrum

2009 ◽  
Vol 79 (1) ◽  
Author(s):  
Christian Kremers ◽  
Dmitry N. Chigrin ◽  
Johann Kroha
1998 ◽  
Vol 51 (3) ◽  
pp. 477
Author(s):  
Ross L. Dawe ◽  
Kenneth C. Hines

A new formulation of the theory of tachyons using the same two postulates as in specialrelativity is applied to the electrodynamics of material media. A discussion of Lagrange’s equations and Hamilton’s equations for ‘classical’ charged tachyons shows that such a formalism is a viable approach. An essay is included on why tachyons can be considered to be localised particles for the purpose of calculations. Tachyonic transformations of the electromagneticfields D, P, H and M are shown to be the same as for bradyonic transformations. Examples discussed include the electric dipole moment of a tachyonic current loop, constitutive equations, polarisation in tachyonic dielectric materials and the velocity of light in tachyonic dielectric media. This is followed by discussions of the collision energy loss for charged tachyonsinteracting with a material medium and a mathematical proof that tachyons cannot emit Cherenkov radiation when passing through a bradyonic dielectric medium.


2019 ◽  
pp. 47-52
Author(s):  
V.A. Balakirev ◽  
I.N. Onishchenko

The process of wakefields excitation by the relativistic electron bunch in dielectric media with ion type of chemical bond is studied. The spatio-temporal structure of the excited wakefield in ion dielectric waveguide is obtained and investigated. It is shown that the excited wakefield in the infrared and longer wavelength ranges consists of the field of longitudinal optical phonons and Cherenkov radiation as a set of eigen electromagnetic waves of the dielectric waveguide.


Author(s):  
Petro P. Trokhimchuck

The problems of the appearance of laser-induced filamets in the matter are discussed. A detailed analysis of the formation of such structures in various media: from air to silicon carbide, is represented. The influence of the spectral composition, the number of pulses and the duration of the irradiation and the medium on the geometric dimensions of the resulting structures and on their phase states is shown. In this case, the sizes of filaments vary from several hundred nanometers for silicon carbide to several hundred meters for air. The emission spectrum is continuous, and resembles the Cherenkov radiation. Therefore, the idea was developed that the radiation of filaments and the radiation of Cherenkov are of the same nature. The problems of the mechanisms of the formation of laser-induced destruction cascades in silicon carbide are discussed. To explain the experimental results, we used modified Rayleigh models (diffraction stratification of the laser beam and critical sizes of nanovoids), physicochemical models for determining critical energy values for the corresponding processes, and models for optically-induced Cherenkov radiation.


2016 ◽  
Vol 16 (2) ◽  
pp. 195-198
Author(s):  
مریم محمدی خشوئی ◽  

1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.


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