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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:46 |
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Conference: Bucharest University Faculty of Physics 2016 Meeting
Section: Theoretical Physics and Applied Mathematics
Title:
Multipole expansion of the interaction energy for an arbitrary current with electromagnetic field in terms of electric, magnetic, and toroid multipoles.
Authors:
E.S. BARNA (1), M.G. MITREA (2)
Affiliation:
1) Department of Structure of Matter, Physics of the Atmosphere and the Earth and Astrophysics, University of Bucharest, Faculty of Physics,Str. Atomistilor, no. 405, Magurele, Ilfov, Romania CP MG-11 RO - 077125, EU
2)Department of Physics, Technical University of Civil Engineering of Bucharest, Lacul Tei bvd, no. 122-124, Code 020396, Sector 2, Bucharest, Romania, EU
E-mail
emil.barna@fizica.unibuc.ro, mitrea_marius_gabriel@yahoo.com
Keywords:
multipole expansion method, electric, magnetic, and toroid multipoles, a proposed vector potential A, calculus of interaction energy, force and torque.
Abstract:
The multipole expansion of a charged current in multipolar moments with highlighting the anapolar moment is stated in the work of Ya. B. Zel’dovich [1] were the weak interaction parity nonconservation was related to this moment. In the electromagnetic interaction, the work of Dubovik and Tugushev [2] and other authors [3-5] are notable. The method can lead to useful description of the vector potential locally, near the origin of a considered coordinates system.
As it follows, the interaction energy of an arbitrary considered current density j with a plane wave electromagnetic (E-M) field will be calculated in the frame of Classical Electrodynamics [6] taking in account the anapolar (also known as toroid) moment.
A vector potential function for the plane E-M wave is proposed close to the origin linked to the current j, wich is observed far from the origin. The current is considered having no divergence and contained in a finite volume. There are taken in account the following: International System of Units (S.I.), the Coulomb gauge fixing conditions, the non-relativistic case.
As results of the above premises, the following results can be mentioned: calculations of the interaction energy, interaction force and torque. The mentioned results are containing the possibility of easy calculation of them by calculating the multipole moments of the considered current j. The toroid moment highlights the direct interaction of the electric field with the current.
References:
1. Ya. B. Zel’dovich, “Parity nonconservation in the first order in the weak-interaction constant in electron scattering and other effects” (Zh. Eksp. Teor. Fiz. 33: 1531 [JETP 6, 1184 (1957)])
2. V. M. Dubovik ,V. V. Tugushev, “ Toroid moments in electrodynamics and solid-state physics”(1990 Phys. Rep. 187 145)
3. E. E. Radescu, G. Vaman, “Exact calculation of the angular momentum loss, recoil force, and radiation intensity for an arbitrary source in terms of electric, magnetic, and toroid multipoles”
(Phys. Rev. E 65, 046609, 1 April 2002).
4. E. E. Radescu, D.H. Vlad, “Angular momentum loss by a radiating toroidal dipoles” (Phys. Rev.E 57, 6030 1 May 1998)
5. A. Costescu, E. E. Radescu, “Dynamic toroid polarizability of atomic hydrogens” (Annals of Physics,Volume 209, Issue 1, July 1991, Pages 13-74)
6. J. D. Jackson, “Classical Electrodynamics” (John Wiley & Sons Ltd. 1962, ISBN: 978-0-471-30932-1)
Acknowledgement:
The authors would like to acknowledge the major contributions in the field of theory of multipole expansion of late professor E. E. Radescu.
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