Laser-ablation ion source with ion funnel

摘要

A laser-ablation ion source is provided for generating a low energy ion beam having low longitudinal and transverse emittance. The ion source comprises a supersonic nozzle (13), followed by an RF ion funnel (23). A laser source (41) generates a laser beam (42) which is focused by a lens (43) to an ablation site (12). The ablation site is located upstream of the nozzle, at a distance of less than 10 mm from the nozzle aperture (14). The laser irradiates the ablation site through the nozzle aperture (14) to generate the ions. A specially designed RF-only ion funnel is also disclosed. Two groups of differently oriented elongate electrodes (25, 25') are staggered along a longitudinal axis (L) and supported by symmetrically arranged supporting rods (24a, 24b) and (24a', 24b').