Collisions of ions with insulator surfaces: charging and discharging dynamics
Résumé
The guiding of ions in keV to MeV energy range by insulator microcapillaries opens interesting perspectives such as direct injection of ions inside a living cell, formation of surface nano-structures, etc. We have studied the dynamic behaviour of charge deposition and beam deflection on insulators having well defined planar geometry when the exact number of charges implanted into the surface, as well as the time evolution of the beam deflection, can be monitored. The used materials, borosilicate, fused silica and quartz, are of interest for production of tapered microcapillaries. Depending on the temperature of the sample, surface composition and structure, charging and discharging dynamics varies by orders of magnitude, giving rise to different guiding effects in insulator microcapillaries. The charging process is compared to simple simulations in order to explain the observed behaviour.