A computerized system for determining secondary ion energy spectra

Abstract

A computer program and computer-directed high-voltage sample potential controller which allow a rapid determination of the energy spectrum of an ion species in a secondary ion mass spectrometer are presented. An electrostatic sector energy analyzer on the mass spectrometer provides high energy resolution. The spectra are obtained by stepping the sample accelerating potential by small voltage steps and determining the detector pulse count rate at each energy. The computer program controls the sample potential, collects the data, makes corrections for ion optical and geometric effects, calculates several important parameters of the energy distribution, and outputs the corrected and uncorrected results to line printer and a plotter. The system is fast, accurate, and very easy to operate. It should be necessary only to change the ion optical correction procedure in order to use the system with other mass spectrometers.