Molecular fragmentation by slow highly charged ion impact

An experimental and theoretical study is presented for fragmentation of D 2 after double-electron removal by slow (1–20 kV) highly charged ion impact (Xe 10 + /19 + and O 5 + /6 + ). As the ratio of the charge state to speed of the incoming ion increases, the D + fragment energies deviate significantly from those found for isolated-molecule Franck-Condon transitions between states of D 2 . Both higher and lower fragment energies are observed, in accordance with predictions based on a Classical Trajectory Monte Carlo model. These energies result from the collisional momentum transfer to the center of mass of the molecule combined with the normal two-body breakup of D + + D + . At the lowest energies, theory predicts a deviation from this vector addition picture due to the high field of the slow projectile.