Theoretical and Mathematical Physics

Energy balance in the coherent scattering of radiation by a system of many particles

L. A. Apresyan, V. I. Krasovskii, S. I. Rasmagin

Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow

Abstract: Using a unified description of the fields of incident and scattered waves, the energy balance conditions for time-averaged energy fluxes during the scattering of a monochromatic wave created by an arbitrary radiation source on a system of particles interacting through scattered fields are considered. A “duality lemma” is obtained for local values of energy fluxes, similar to Lorentz lemma for fields from two sources and determining the redistribution of energy fluxes between scatterers and the source. The total energy flow is divided into “energy” and “interference” parts, each of which has its own source function localized on particles, and which are preserved during propagation in free space. The variants of the optical theorem corresponding to various subsystems (clusters) are described, as well as their relationship to the Purcell factor. The result is a detailed picture of energy exchange for arbitrarily chosen clusters of interacting particles.

Keywords: multiple scattering, coherent radiation source, energy conservation, optical theorem, Purcell effect, radiation losses.

Received: 08.11.2024
Revised: 21.02.2025
Accepted: 24.02.2025

DOI: 10.61011/JTF.2025.08.60893.412-24

Bibliographic databases:

•