Apparatus for the Study of the Electron Impact Desorption of Ions and Neutrals from Solid Surfaces

A cylindrical magnetic spectrometer for the study of the electron impact desorption of ions and neutrals from solid surfaces is described. The instrument has an energy resolution of approximately 4% and sufficient sensitivity to allow the measurement of the ion energy distributions for systems in which the ion yield is 10−9 ions per electron or greater. In addition, the apparatus allows the determination of the mass-to-charge ratio of the emitted ions. The design of the apparatus and experimental procedures are discussed. Examples of typical measurements are reported.