Bremsstrahlung of Slow Electrons in Neutral Gases and Free‐Free Absorption of Microwaves

Abstract

Bremsstrahlung of nonrelativistic electrons in a neutral gas is investigated including the polarization and exchange effects. The intensity and spectrum of the bremsstrahlung and of the induced dipole radiation are obtained for a Maxwellian distribution of electron energy in terms of the elastic scattering cross section of the atom for electrons and its polarizability. The interference of the induced dipole radiation with the bremsstrahlung is also considered. It is found that the exchange effects and the induced dipole radiation are negligible as far as the total radiated power is concerned. The latter, however, may be important at the short‐wave end of the spectrum. Finally, the absorption coefficient is obtained from the bremsstrahlung cross section. The results are evaluated explicitly for a Maxwellian distribution.