Fragmentation of molecules under charge-changing collisions of a few MeV heavy ions

We investigated molecular fragmentation of CO and C₂H₂ molecules by impact of various fast heavy ions. Fragment ions produced in electron capture and loss collisions of projectile ions were measured in coincidence with final projectile charge states. Data acquisition using position sensitive detection system allows us to obtain 3D momentum imaging of fragment ions and kinetic energy release (KER) in various charge-changing collisions. It was found that the KER spectra show strong dependence on the type of charge-changing collisions. This may be caused by the difference of impact parameters associated with individual charge-changing collisions. Moreover we revealed the different fragmentation pathway between ion impacts and photoionization