A new two-dimensional particle detector for a toroidal electrostatic analyzer

We describe a new two-dimensional detector for the detection of ions scattered from a solid target, analyzed in energy and scattering angle by a toroidal electrostatic analyzer. The detector resolves the scattering angle with a resolution of 0.4° over a range of 25°, and the ion energy with a resolution of 120 eV over a range of 2000 eV, at 100 keV ion energy. The energy resolution of the spectrometer was improved with a factor 4 relative to its previous performance with a one-dimensional scattering angle detector, while−at the same time−the dose efficiency (count/μC) was improved by a factor 5–10.