Compton scattering of relativistic electrons in compact X-ray sources

Abstract

The problem of single Compton scattering is considered and the resulting spectrum, angular distribution and polarization of scattered photons in a general case are obtained. The inverse Compton scattering (ICS) for arbitrary energies of electronsE and photons ω₀ is investigated in detail. In the case of isotropically-distributed initial photons and relativistic electrons, a strong rise of the scattered spectrum near the upper edge takes place, starting from the values of the characteristic parameterb≡4Eω ₀≳10 (in units of mc²=1). The energy-loss rate of relativistic electrons due to ICS is calculated. It is shown that the relativistic electrons of the energiesE≳100 MeV, when scattering on the X-rays with ω₀~10KeV, transmit the dominant part of their energy to the photons which fall after scattering into the energy range of the electrons (≳100 MeV).

The radiation spectrum of ICS, as well as the energy-losses of relativistic electrons distributed by power-lawE ^−α, are calculated. The radiation spectrum reveals the power-law behaviour with the different indices in two limits: the dependence ω^−(αα1)/2 at ωω₀≪1 gradually changes to ω^−(α+1) ln (ωω₀) law for ωω₀≫1.