DIFFERENTIAL CROSS-SECTIONS FOR LASER-ASSISTED ELASTIC ELECTRON-SCATTERING FROM ARGON

We report experimental measurements of the differential cross sections for scattering of electrons in the range 8-20 eV from helium and argo n through scattering angles of 10 degrees-140 degrees in the presence of a high intensity (similar to 10(8) W cm(-2)) carbon dioxide laser. The majority of the results reported are scattering from argon under c onditions for which the Kroll-Watson approximation, usually applied to these types of measurements, predicts zero cross sections. The cross sections reported range up to similar to 12% of the appropriate field- free elastic scattering cross sections in strong disagreement with the theoretical predictions.