DIFFERENTIAL CROSS-SECTIONS OF LOW-ENERGY ELECTRON-HYDROGEN SCATTERING IN A CO2-LASER FIELD

Floquet close-coupling (FCC) analysis of stimulated electron-hydrogen scattering in the field of a low-frequency CO2 laser field is carried out. Results are obtained for one-, two- and three-photon absorption a nd emission processes in terms of the differential scattering cross se ctions as a function of the scattering angle. Two critical geometries are considered in which the argument of the Bessel function in the wel l known low-frequency;formula becomes negligibly small. It is found th at the ratios of the cross sections for small-angle scattering in both geometries are many orders of magnitude larger than predicted by the low-frequency formula (LFF). The result supports an analogous finding of many orders of magnitude larger values of the cross section measure d in Ar and He by Wallbank and Holmes, and confirms the failure of LFF for small-angle scattering.