Cyclotron absorption of X rays by a classical plasma in the strong magnetic fields of neutron stars

The cyclotron absorption of electromagnetic waves in an equilibrium classical plasma in a strong magnetic field is investigated on the basis of a kinetic equation and by means of Kirchhoff's law. A study is carried out of the influence of vacuum polarization by the magnetic field on the polarization of the ordinary and extraordinary waves and on the coefficients of cyclotron absorption of these waves in the plasma. The results obtained are of interest for the theory of the emission of X-ray sources associated with neutron stars in binary systems and above all for the theory of the origin of the X rays in the spectrum of the source Her X-1