Fragmentation and desorption in low-energy highly charged ion collisions with molecules and surfaces

In order to study secondary-ion emission in low-energy highly charged ion collisions with molecules and surfaces, we performed coincidence measurements of secondary ions and scattered ions, scattered neutral atoms or secondary electrons. Fragmentation and desorption processes induced by electron captures were successfully extracted by observing the scattered ions/atoms with small scattering angles. Momentum imaging of the secondary ions offers a new analysis method when combined with translational energy spectroscopy or energy-gain spectroscopy of scattered ions. This technique was successful in clarifying the reaction pathways of the electronic transitions of molecules and following the dissociation processes in collisions between Arq+ (q 3–12) and CF4 and N2 molecules. We also successfully performed secondary ion mass spectroscopy of the topmost layers of the surfaces in glancing collisions between Ar8+ and both GaN (0001) and (000 1) surfaces.