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.