The scattering coefficient of highly excited atomic levels formed by recombination from a plasma and energetically broadened by plasma field fluctuations is determined. For this purpose, the population of the levels is calculated from a detailed balance equation which is solved consistently together with the corresponding equation for the free electron spectrum. Numerical results are obtained for parameters appropriate for ionospheric conditions. The solution proves to be in no way related to LTE situations, therewith invalidating usual treatments of the problem, which are not consistently based on a detailed balance approach. The theoretical result for the equilibrium coefficient for resonant scattering of radio waves by Rydberg atoms is consistent with experimental data obtained from the ionosphere. This suggests that the considered mechanism is exclusively responsible for the scattering of radio waves in particular and electromagnetic radiation in general. SUMMARY•
A consistent classical wave optics approach to the theory of the Michelson–Morley experiment shows that the original theory as applied by Michelson and Morley and others does not calculate the optical paths of the two beams correctly, primarily because of incorrectly assuming a right angle reflection in the instrument’s reference frame for the transverse beam, but also because of the incorrect assumption of aberration for the wave fronts. The theory presented in this work proves the expected variation of the phase difference when rotating the interferometer to be more than twice as large and also strongly asymmetrical around the zero line.
Analysis of the geocoronal He-I 58.4-nm resonance radiation field with rocket borne gas absorption cell photometers has revealed singly scattered photons to attain steadily increasing importance in the radiation signals if photons close to the line center are effectively suppressed. In order quantitatively to confirm this, we have reinvestigated the radiation transport problem and have given the spectral intensity in terms of contributions from different scattering orders. In the formulation of these contributions we have used the concept of angle-dependent partial frequency redistribution in comparison with that of complete redistribution. The first and second order intensity contributions are studied in detail here with respect to their spectral profile, to their local and solar zenith angle dependence, and to their height profile. The second and higher order intensity contributions are shown to decrease steeply with increasing distance from the line center, such that for a specific observation a critical wavelength distance can be calculated beyond which only singly scattered photons contribute to the total intensity. The intensity due only to singly scattered photons is proven to be proportional to the helium column density on the line of sight within clearly determinable accuracies. Thus its height profile enables immediate deduction of local atmospheric parameters, as the atmospheric helium density and temperature, even under optically thick conditions. Fahr and $eidl; 1978, H. J. Fahr et al., unpublished manuscript, 1981]. This is due to the fact that resonance gas absorption cell photometers can selectively suppress photons that are within a specific distance A Xc from the center of the resonance line. A broadband photometer with a pressurized resonance cell in front is thus able to register only those photons of the incomi ng radiation intensity that are beyond this specific wavelength distance. 1977;The interesting fact with these transmitted intensities, as obtained in the case of He 1 58.4 nm observations in the He geocorona, is that their logarithmic plot versus height above the planetary surface, in very good approximation, yields a redistribution process (see section 5) the above conclusion is not reached. For the purpose of a theoretical confirmation of the above mentioned conclusion we have reinvestigated the problem of the resonance radiation transport in a threedimensional planetary atmosphere under the scope of representing separately radiation contributions from different scattering orders. Basic treatments of the radiation transport problem applied to plane parallel atmospheres have been published by Chandrasekhar [1960] and $obolev [1963]. More realistic three-dimensional structures of the planetary atmosphere cannot be treated analytically, but can only be carried out by numerical computations. A first calculation of the geocoronal Lyman-Alpha resonance field was carried out by Thomas [ 1963] with the help of an iterative procedure to determine alternatingly source function and radiation...
The retardation equation for straight line signal propagation is solved analytically for the two-dimensional case and used to plot the retarded positions graphically for a variety of particle distributions moving relatively to the observer. The results show that in case of a finite signal propagation speed the observed particle distribution must appear as expanded/compressed if it moves towards/away from the observer. The apparent change of scale of the distribution goes hereby along with an inverse change in particle density.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.