Non-resonant photo ionisation of neutral particles within gas - using laser emission with intensity above saturation level of particles for ionisation

摘要

The ionisation is produced with a system that uses a laser emission (10) directed onto a plate capacitor arrangement that has a pair of parallel plates (11, 12) in a homogenous electrical field. A lens (13) focuses the emission at the centre of the plates. Ions are extracted (14) through an opening in the negatively charged plate. The intensity of the laser emission lies above the saturation intensity for ionisation of the neutral particles. USE - For surface analysis by laser ionisation, or secondary ion mass spectroscopy.