The System
The GCIB 40 system comprises:
- Ion source, comprising cluster generation and ionization chambers.
- Ion optical column, including a mass filter.
- Power supplies to drive the ion source and column.
- Source pumping system.
Gas clusters are formed by adiabatic expansion and then ionised by electron bombardment.
The cluster ions are accelerated into an ion column which contains a Wien filter, 5 selectable apertures (for selection of current and spot size ranges), a gate valve (for isolation of source from instrument during maintenance), a pulsing unit, a bend to remove neutrals, scan plates and a final focussing lens.
The Wien filter selects single cluster sizes for the small clusters; for the larger clusters (~Ar100 upwards) the beam consists of a mass distribution around the
nominal cluster size.
The GCIB 40, with its high-energy gas cluster analysis beam, offers better signal with low damage in organic SIMS analysis, with < 3 microns spatial resolution.
