Molecular beam studies of total cross sections of Na scattered by different gases

A molecular beam scattering apparatus has been set up for the study of total cross section of alkali and alkali halide molecules scattered by different gases. The resolution of the apparatus is fairly high so that accurate correction for finite resolution can be made. The Ishii-Nakayama backstreaming effect of the McLeod gauge used for calibration purpose has been eliminated. The scattering cross sections for Na atom with Ar, O2, N2, He and H2 have been measured. The results show the satisfactory performance of the apparatus. The cross sections obtained have been compared with the theoretical values. (auth.)