Open AccessFeatures of photon diffusion in a dispersed medium
Author(s) -
A. V. Galaktionov
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2100/1/012022
Subject(s) - photon diffusion , diffusion , photon transport in biological tissue , diffusion equation , photon , refractive index , thermal conductivity , thermal diffusivity , heat equation , heat transfer , dimension (graph theory) , physics , limit (mathematics) , thermal radiation , variable (mathematics) , optics , thermodynamics , quantum mechanics , mathematical analysis , mathematics , monte carlo method , light source , statistics , economy , dynamic monte carlo method , direct simulation monte carlo , pure mathematics , economics , service (business)
Energy transfer by thermal radiation in a dispersed medium with a variable refractive index is discussed. This transfer can be described by a surprisingly simple diffusion equation. The process is naturally to interpret as the photon diffusion. The diffusion equation is free from strict conditions of applicability of the radiation transfer equation, which are usually not satisfied in disperse media with densely packed inhomogeneities. Quantum constraints on the value of the photon diffusion coefficient are derived. These restrictions turn out to be similar to the conditions for the applicability of geometric optics. The lower limit of the thermal conductivity coefficient is obtained, which is easier to verify in the experiment. An independent derivation of this limitation is given from considerations of symmetry and dimension.