An Ion Energy Analyzer with On-Board Data Reduction

An ion energy analyzer with on-board data reduction techniques has been developed to measure ion temperature and ion concentration with very high temporal resolution. The basic concept employed is to differentiate the characteristic volt-ampere curve within the instrument and to detect and store the maximum of the differentiated signal. This information coupled with the maximum ion concentration, obtained when the sweep voltage is negative, is sufficient to determine the ion temperature even when three different ion mass groups (molecular ions, atomic ions, light ions) are present. Consequently, high temporal resolution ion temperatures may be obtained with very limited telemetry bandwidth.