Polarization-interference effects in the bremsstrahlung of quasiclassical electrons on ions with a core

The polarization dependence of the stimulated bremsstrahlung and inverse br emsstrahlung (SBIB) of quasiclassical electrons on highly charged ions with a core is calculated in the approximation of a specified Coulomb current. Emission frequencies close to an eigenfrequency of the ion core are conside red. The contributions of the static and polarization channels are taken in to account in the amplitude of the process. When the nondipole nature of th e interaction between the incident particle and a resonant transition in th e ion core is taken into account, interference between these channels cause s the spectral-amplitude characteristics of the process to assume a specifi c dependence on the angle alpha between the electric field intensity vector of the electromagnetic wave and the initial velocity vector of the inciden t particle. This dependence, which persists after integration of the cross section over the scattering angle of the incident particle, causes interfer ence effects, viz., asymmetry of the line shape and dips in the dependence of the SBIB cross section on electric field intensity, to appear for alpha = pi/2 and significantly reduces them for alpha = 0. (C) 1999 American Inst itute of Physics. [S1063-7761(99)00705-2].