High frequency spectral distribution of the equilibrium radiation energy in a plasma
We establish that the difference of the spectral distribution of the equilibrium radiation energy in matter from the Planck formula in the high frequency range is determined by the imaginary part of the transverse dielectric permittivity of the matter. Based on this, we show that in a rarified high temperature fully ionized nonrelativistic plasma, the high frequency spectral distribution of the equilibrium radiation energy differs essentially from the Planck formula because of the power law character of the decrease in the frequency, which is due to the presence of matter.