Fully Differential Cross Sections for Electron-Impact ionization of aligned molecules

Most experiments measuring electron-impact ionization of molecules do not determine the orientation of the molecule at the time of ionization. One way to determine the orientation is to simultaneously ionize the molecule and excite the residual ion to a state that will dissociate. The orientation of the molecule can then be determined by detecting one of the dissociation fragments since the fragments will leave in the direction of orientation. We will present Fully differential cross sections for 176 eV electron-impact dissociative excitation-ionization of oriented H2. These results show a strong dependence of the dissociative ionization-exictation process on the alignment of the internuclear axis with respect to the projectile momentum and emission directions of the scattered and ejected electrons.