Electron impact ionization of molecules at low to intermediate energies-A search for Young's double slit type interferences

Experimental and theoretical work studying the (e,2e) collision process from diatomic molecules is reported. In particular, recent work carried out from near threshold to ∼100 eV incident electron energy ionizing H2 and N2 in coplanar symmetric and asymmetric geometries is compared to calculations using a molecular three body distorted wave model. Of interest is the possibility of observing the effects of Young's double slit-type interference terms in the measured cross-sections. There is considerable interest in this type of scattering, since simple models predict the effects should be equivalent to a modulation of the cross-section from individual atoms which constitute the molecule. Such effects have recently been inferred at 250 eV incident energy in an asymmetric geometry, however at lower energies the complexity of the scattering process and the requirement to integrate over all possible alignments of the targets means that these effects remain unclear. Experimental data and results from a molecular three-body distorted wave (M3DW) model are presented, and possible methods to experimentally align and detect the molecular direction prior to ionization are suggested.