Importance of projectile-target interactions in the triple differential cross sections for Low energy (e,2e) ionization of aligned H$_{2}$

Experimental and theoretical Triple Differential Cross Sections (TDCS) are presented for electron impact ionization-excitation of the $2s\sigma_{g} $state of H$_{2}$ in the perpendicular plane. The excited $2s\sigma _{g} $ state immediately dissociates and the alignment of the molecule is determined by detecting one of the fragments. Results are presented for three different alignments in the xy-plane (scattering plane is xz) - alignment along y-axis, x-axis, and 45$^{\circ}$ between the x- and y-axes for incident electron energies of 4, 10, and 25 eV and different scattered electron angles of 20$^{\circ}$ and 30$^{\circ}$ in the perpendicular plane. Theoretical M4DW (molecular 4-body distorted wave) results are compared to experimental data, and overall we found reasonably good agreement between experiment and theory. The Results show that (e,2e) cross sections for excitation-ionization depend strongly on the orientation of the H$_{2}$ molecule.