Mass-spectrometer measuring ions and neutral particles - uses retractable probe and HF-plasma for neutrals

摘要

The beam from a primary ion source (3) in a vacuum vessel (1) passes through a raster system (15) onto a probe which is retractable from the lens stage (8) and is a source of secondary ions (6a, 6b). The ions are drawn off by a snow plough electrode and focussed through an electrostatic lens (11) into a mass-spectrometer (12). When the probe is lowered below the lens stage (6b) the neutral particles are ionised in an HF-plasma generated in the lower section by admitting gas through a differential pumping-system. ADVANTAGE - Enables analysis of sec. ions and neutral particles from same ion-source.