CC BY
11Complex Systems of Charged Particles and their Interactions with Electromagnetic Radiation 2018
ON THE POWER TAIL OF THE SPECTRAL DENSITY DISTRIBUTION OF THE EQUILIBRIUM RADIATION IN A PLASMA
V.B. Bobrov 1 2, S.A. Trigger 1
1 Joint Institute for HighTemperatures, Russian Academy of Sciences, Moscow 2 National Research University "MPEI", Moscow e-mails: vic5907@mail.ru; satron@mail.ru
The study of thermal radiation plays an essential role in the consideration of many phylsical phenomena (see, e.g., [1]). The necessary point is the consistent accounting of the relationships connecting the characteristics of equilibrium radiation with the electromagnetic properties of matter [2]. As was shown earlier [3-5], the calculation of the spectral distribution of the energy of equilibrium radiation, the presence of a substance, leads to a difference in the spectral density of equilibrium radiation (SDER) from the well-known Planck formula corresponding to the model of an absolutely black body (see, e.g., [2-4]). This is even more important because the Planck distribution corresponds to the equilibrium ideal gas of photons, while the presence of a small amount of matter is necessary for the possibility of attainment of equilibrium radiation, since in the nonrelativistic theory there is no direct interaction between the photons [2]. It is generally accepted that the equilibrium properties of an ideal gas of photons represent the ultimate properties of a real system of an electromagnetic field and a substance in thermodynamic equilibrium. In this paper, an analysis of the SDER in the presence of a substance is presented and it is found that finite value of the imagine part of the plasma dielectric function determines the deviation of the SDER from the Planck distribution. In particular, the presence of a plasma leads to the appearance of a long power tail of the SDER at high frequencies. The developed approach is based on the calculation of the SDER for the quantized electromagnetic field under completely equilibrium conditions, in contrast to the approach associated with calculating the plasma energy change as a response of the system to the effect of external sources [6], which lead to a difference in the results of these two approximations.
1. M.L. Levin, S.M. Rytov. The Theory of Equilibrium Thermal Fluctuations in Electrodynamics. M.: Nauka(1967) 308 p.
2. L.D. Landau, E.M. Lifshitz, Statistical Physics, part 1, "Science" Publishing, Moscow (1976)
3. S.A. Trigger, Physics Letters A 370, p. 365 (2007)
4. V.B. Bobrov, I.M. Sokolov, S.A. Trigger. JETP Lett., 110, 299 (2015)
5. V. B. Bobrov, S. A. Trigger Theoretical and Mathematical Physics, 192(3): 1396-1407 (2017)
