ELECTRON-IMPACT IONIZATION OF HELIUM IN THE COPLANAR EQUAL ENERGY-SHARING GEOMETRY

In this paper the triple differential cross sections for electron impa ct ionization of helium in the coplanar equal energy-sharing geometry is considered. A new collision process called triple-binary collision is identified in the situation where the angle of the two outgoing ele ctrons is fixed. It has been shown how the dominant collision mechanis ms change as the incident energy increases. It has also been shown how the exchange effects contribute to the cross sections.