A mass and energy spectrometer for secondary ion analysis

Abstract

An apparatus for studying the physical processes of secondary ion emission from ion-irradiated targets is described. The system uses a spherical electrostatic energy analyser and a quadrupole mass spectrometer both operating at fixed pass energy. Energy scanning is achieved using a retarding/accelerating field system. The apparatus is used for the study of the spatial and energy distributions of secondary ions and consequently its design parameters differ from those of a secondary ion apparatus intended solely for mass spectrometry studies. The system has an angular resolution of less than 1 degrees , an energy window Delta E approximately=1 eV, a mass resolution of 60 and optimum signal sensitivity of approximately 10^-8 counts per primary ion. Details of the design, analysis and testing of the system are presented.