GEC Student Award for Excellence Finalist: Atomic and Molecular Signatures for charged particle ionization

Charged particle ionization of atoms and molecules has been studied over several years and two prominent features are observed for both atoms and molecules -- one where the bound electron is ejected in a direction which conserves momentum for a classical projectile-electron collision (the binary peak) and a smaller feature where this electron is ejected in the opposite direction (recoil peak). These conventional studies are all performed in the projectile scattering plane. Here we report results for a plane perpendicular to the conventional plane, and we find two new features -- one the same for both atoms and molecules and one completely opposite. Quantum calculations are used to ascribe simple classical descriptions to these features.