Asymptotic Solutions of Dipoles in a Semi-infinite Medium


Book Description

A theoretical analysis is made of the electromagnetic fields in two homogeneous media separated by a plane interface with a point source located in the denser medium. The solution is expressed in the form of integrals which cannot be evaluated explicitly. Asymptotic evaluations of the integrals have been made by many investigators using the saddlepoint technique. In the present work, all known asymptotic results are presented in one comprehensive form, using a modification of the method suggested by Lighthill for the asymptotic evaluation of the Fourier integrals. The regions of validity of the solutions are indicated wherever possible. The advantage of this method over others is its ease and simplicity. The present results agree term by term with the earlier ones of Banos and Wesley (1953-1954), and Paul (1959), who investigated the case of a source and receiver close to the interface, and an arbitrary location of source and receiver, respectively. The results obtained in the report are also compared with those of Stein (1955). (Author).



















A Discussion of the Wheeler-Feynman Absorber Theory of Radiation


Book Description

The Wheeler-Feynman absorber theory of radiation is reviewed. A proof is offered to show that a sum of advanced and retarded effects from the absorber can provide the origin of radiative reaction. This proof is different from and perhaps simpler than that of Wheeler and Feynman. From arguments of momentum and energy conservation the necessity of the absorber for the emission of radiation is demonstrated for three cases. (Author).







Space Electricity


Book Description




Hydromagnetic Ionizing Waves


Book Description

A theory of hydromagnetic ionizing waves has been developed which is valid in the region in which gas pressure is negligible, compared with magnetic pressure. The theory takes into account the energy expended in partial ionization of the gas behind the wave. The usual high conductivity boundary condition behind the wave is not employed. The electric field in front of the wave is taken as a parameter. Results of this theory are compared with available experimental measurements, and show good agreement. (Author).