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
(Xe10+/19+ and O5+/6+). As the ratio of the charge state to speed of the in
coming ion increases: the D+ fragment energies deviate significantly from t
hose found for isolated-molecule Franck-Condon transitions between states o
f D-2. Both higher and lower fragment energies are observed, in accordance
with predictions based on a Classical Trajectory Monte Carlo model. These e
nergies 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 t
he lowest energies, theory predicts a deviation from this vector addition p
icture due to the high field of the slow projectile.