ALIGNMENT AND ORIENTATION EFFECTS FOR THE INDIRECT IONIZATION OF CH3CL IN THE VERTICAL-BAR-111] ROTATIONAL STATE BY FAST-ELECTRON IMPACT

The steric opacity function, which includes alignment and orientation effects, for the indirect ionization process of CH3Cl+ has been obtain ed and analyzed from the study of fast electron impact of the oriented CH3Cl molecule with the well-defined orientation of the \JKM]) = \111 ] state. On the basis of a particle collision approximation for the pr ojectile electron and the target molecular orbital electrons, both ori entation and alignment dependences have been clarified by the ab initi o calculations of the HOMO electron densities of the molecule. A good correlation between the site-specific ionization cross section and the cross section of the spatial distribution of 2e HOMO electrons of CH3 Cl was confirmed.