ELECTRON-METASTABLE-HELIUM DIFFERENTIAL AND INTEGRAL CROSS-SECTIONS

The differential and integral cross sections for the excitation of the 2(3)P and the 3(3)L (L = S, P and D) states of He from the metastable 2(3)S state are calculated using the semiclassical multichannel eikonal theory with a nine-channel basis set. Comparison is made with the recent experimental results of Muller-Fiedler et al and Rall et al for the differential and integral cross sections, respectively. The agreement between the present multichannel eikonal results and the experimental data for the 3(3)S and 3(3)D differential cross sections is satisfactory. However, significant differences are noted between the experimental data and the present multichannel eikonal theory for the 2(3)S --> 2(3)P, 3(3)P differential cross sections.