Multiple ionization and fragmentation of the DNA base thymine by interaction with C q+ ions

Ionization and fragmentation of the DNA base thymine uponinteraction with keV C^q+ ions(q = 1 -6) has been studied. By means of time-of-flightspectrometry of two or more thymine fragments in coincidencewith an ejected electron we could investigate particulardissociation channels by means of their associatedkinetic-energy-release. The fragmentation dynamics are stronglyinfluenced by the C^q+ charge state:for low q values mainlyfragmentation due to direct collisions is observed. Withincreasing q, electron capturebecomes more important. For larger q we could identify several Coulombexplosion channels, leading to very energetic fragments.