SMALL-ANGLE SCATTERING OF SLOW-ELECTRONS BY HELIUM-ATOMS IN A CO2-LASER FIELD - A COLLECTIVE MODEL

According to recent experiments by Wallbank and Holmes (1993 Phys. Rev . A 48 R2515; 1994 J. Phys. B: At. Mol. Opt. Phys. 27 1221) on small a ngle, slow electron scattering by He atoms in a CO2-laser field, the o bserved cross section data on free-free transitions are by many orders of magnitude larger than the predictions by the Kroll-Watson scatteri ng formula (1973 Phys. Rev. A 8 804), which are based on the considera tion of scattering in a laser held by a single atom. Instead, we show here that a simple model of the collective and coherent scattering of electrons by a quasi-macroscopic laser-induced polarization potential reproduces the observed data surprisingly well.