Laser-induced free-free transitions in elastic electron scattering from CO2

This paper presents measurements of laser-induced free-free transitions of electrons scattered from CO2 molecules in the ground electronic state at incident electron energies of 3.8 and 5.8 eV under a pulsed CO2 laser field. The differential cross section of free-free transitions involving absorption and emission of up to two photons was measured at various scattering angles with the polarization of the laser either parallel with or perpendicular to the momentum change vector of the scattered electrons. The results of the parallel geometry are found to be in qualitative agreement with the predictions of the Kroll-Watson approximation within the experimental uncertainty whereas those of the perpendicular geometry show marked discrepancy with the Kroll-Watson predictions.