Nonlocal radiative forces in fully-ionized plasmas

Abstract

The solution of the Fokker–Planck equation which contains the contribution of high-frequency electric fields is presented. For this, the projection operators of the Krook collision operator and the semicollisional propagator computed with the continued fractions were used. Both elastic and inelastic momentum transfer from the high-frequency electric field to electrons have been considered. The contributions of such high-frequency electric fields to the stress tensor and to the mean change of momentum due to electron–ion collisions are derived in the whole collisionality range. As a result, in the collisionless range, these contributions led to a new force which is 1.6 (instead of 4/3) more important than the Miller force. In the collisional range, the radiative force due to the inverse bremsstrahlung absorption is recovered and a new contribution which arises from the mean change of momentum due to collisions is found.