9,772 research outputs found
Three-Body Dynamics and Self-Powering of an Electrodynamic Tether in a Plasmasphere
The dynamics of an electrodynamic tether in a three-body gravitational environment are investigated. In the classical two-body scenario the extraction of power is at the expense of orbital kinetic energy. As a result of power extraction, an electrodynamic tether satellite system loses altitude and deorbits. This concept has been proposed and well investigated in the past, for example for orbital debris mitigation and spent stages reentry. On the other hand, in the three-body scenario an electrodynamic tether can be placed in an equilibrium position fixed with respect to the two primary bodies without deorbiting, and at the same time generate power for onboard use. The appearance of new equilibrium positions in the perturbed three-body problem allow this to happen as the electrical power is extracted at the expenses of the plasma corotating with the primary body. Fundamental differences between the classical twobody dynamics and the new phenomena appearing in the circular restricted three-body problem perturbed by the electrodynamic force of the electrodynamic tether are shown in the paper. An interesting application of an electrodynamic tether placed in the Jupiter plasma torus is then considered, in which the electrodynamic tether generates useful electrical power of about 1 kW with a 20-km-long electrodynamic tether from the environmental plasma without losing orbital energy
Efficient Evaluation of Casimir Force in Arbitrary Three-dimensional Geometries by Integral Equation Methods
In this paper, we generalized the surface integral equation method for the
evaluation of Casimir force in arbitrary three-dimensional geometries. Similar
to the two-dimensional case, the evaluation of the mean Maxwell stress tensor
is cast into solving a series of three-dimensional scattering problems. The
formulation and solution of the three-dimensional scattering problem is
well-studied in classical computational electromagnetics. This paper
demonstrates that this quantum electrodynamic phenomena can be studied using
the knowledge and techniques of classical electrodynamics.Comment: 9 pages, 2 figure
A classical calculation of the leptonic magnetic moment
In this paper we will show that purely classical concepts based on a few
heuristic considerations about extended field configurations are enough to
compute the leptonic magnetic moment with corrections in -power
perturbative expansion.Comment: 5 page
Classical microscopic theory of dispersion, emission and absorption of light in dielectrics
This paper is a continuation of a recent one in which, apparently for the
first time, the existence of polaritons in ionic crystals was proven in a
microscopic electrodynamic theory. This was obtained through an explicit
computation of the dispersion curves. Here the main further contribution
consists in studying electric susceptibility, from which the spectrum can be
inferred. We show how susceptibility is obtained by the Green--Kubo methods of
Hamiltonian statistical mechanics, and give for it a concrete expression in
terms of time--correlation functions. As in the previous paper, here too we
work in a completely classical framework, in which the electrodynamic forces
acting on the charges are all taken into account, both the retarded forces and
the radiation reaction ones. So, in order to apply the methods of statistical
mechanics, the system has to be previously reduced to a Hamiltonian one. This
is made possible in virtue of two global properties of classical
electrodynamics, namely, the Wheeler--Feynman identity and the Ewald
resummation properties, the proofs of which were already given for ordered
system. The second contribution consists in formulating the theory in a
completely general way, so that in principle it applies also to disordered
systems such as glasses, or liquids or gases, provided the two general
properties mentioned above continue to hold. A first step in this direction is
made here by providing a completely general proof of the Wheeler--Feynman
identity, which is shown to be the counterpart of a general causality property
of classical electrodynamics. Finally it is shown how a line spectrum can
appear at all in classical systems, as a counterpart of suitable stability
properties of the motions, with a broadening due to a coexistence of
chaoticity
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