A semi-relativistic distorted wave calculation of electron impact excitation of gold

A semi-relativistic distorted wave method has been developed to calculate t he differential cross section (DCS) and Stokes parameters for electron impa cting excitation of gold atom at 30 cV. At large angle ( greater than or eq ual to 60 degrees) our DCS results are within the experimental error limit. At small angle (less than or equal to 60 degrees) our DCS results deviate a little from the experimental data. In the whole range our DCS data are ro ughly the same as those of complete relativistic distorted wave (RDW) metho d. The P-1 and P-2 calculated from our semi-relativistic method both in str ucture and tendency are similar to those of the complete RDW method. In par ticularly, -P-3 calculated from two kinds of relativistic methods are almos t the same in magnitude and structure. The difference between our results a nd those of complete RDW method may come from the neglecting direct relativ istic of incident electron in our calculation. By comparing the results wit h those of experiment and complete RDW method it is deduced that the semi-r elativistic distorted wave is a convenient and reliable method.